18:39: Maxim Eristavi
tweets: While Independence square is burning and stun grenades are exploding, protesters are signing national anthem. It's like a doomsday.
18:43:
The protest camp in the heart of Kiev is reported to be engulfed in flames as police advance on protesters.
18:50:
During the day, at least nine people were killed, including two policemen, as protesters and security forces clashed in the worst violence in weeks
Johann Kwan
tweets: I just got a translation of the police megaphone. They're asking women and children to leave, as they're starting an anti-terror op.
Nataliya Gumenyuk
tweets: 5th channel - the biggest news channels which show the protest on TV shut down around the country
19:02:
A member of the security forces is seen on a roof, carrying a gun, during clashes with anti-government protesters in Kiev
Several tents pitched by anti-government protesters in Independence Square have been set on fire, according to images on Ukrainian television. Security forces are said to be circling the square in an apparent bid to clear the protesters.
David Stern BBC News, Kiev
tells BBC World this is a key moment for people in Ukraine. He says many people are scared of an escalation beyond what the country is seeing tonight. Although this does not necessarily mean a civil war - as previously suggested by some - Ukraine remains dangerously divided.
Olga, in Kiev,
emails: At the moment the police at the Independence Square in Kiev are announcing the start of what they call 'anti-terrorist operation'. Against more than 20,000 anti-government protesters - they are students, retired, men and women, who are just fighting for their right to live in a country, free of corruption and dictatorship. People keep coming to the main square despite the closed tube, they are scared, but they feel they have nothing to loose.
19:19:
Some 25,000 protestors remained on Independence Square after the expiry of the 18:00 local time (16:00 GMT) ultimatum to leave, according to news agency AFP.
19:41:
Ukrainian television presenter Artem Ovdiyenko has posted on Facebook saying that Ukraine's private news channel 5 Kanal TV is now only available on the internet.
"5 Kanal is now available only online, live broadcasting has been completely shut down across the country", he said.
email:
Ksenia, in Kiev
emails: All roads leading to Kiev are blocked by police to prevent more Ukrainians from joining the protests. The metro is still closed. It is impossible to get to the city centre by car. 5th channel - the channel which broadcasts the protests - has been blocked.
Gorshenin Institute
tweets: national anthem sung by protesters while being attacked by police and other detachments impresses
19:55:
Police have been coming under a hail of rocks thrown by protesters.
19:58:
Opposition leaders are addressing the protesters, urging them to remain in the square.
Dan Peleschuk
tweets: Defiant #euromaidan protesters belting heart-wrenching patriotic, wartime songs as fighting and flames rage around them.
20:27:
Several thousand protesters have seized the state regional administration building in the western Ukrainian city of Lviv, reports news agency Interfax.
20:29:
Opposition leader Vitali Klitschko has urged the protesters to defend the camp. "We will not go anywhere from here,'' Mr Klitschko told the crowd, speaking from a stage as fires burned around him. "This is an island of freedom and we will defend it,'' he said.
Breaking News
Attacks on government offices, police and the security service, SBU, are reported in several cities in western Ukraine, including Lviv, Ternopil and Ivano-Frankivsk, according to the opposition-supporting Fifth TV channel, which has been switched off across Ukraine and is available only on satellite and online.
Breaking News
At least 13 people are now believed to have been killed in the violence today. Police say six policemen have been shot dead.
Mike Pheonix, in Kiev,
emails: I'm an American living here 14 years. The situation is getting worse by the minute. BBC TV was cut off last week. Tonight channel 5 - The opposition network owned by Poreschenko had their TV and internet sites cut off. We fear a blood bath.
21:26:
Ukrainian opposition leader Vitali Klitschko has arrived at President Viktor Yanukovich's office for talks, Reuters quoted Mr Klitschko's spokeswoman as saying.
21:28:
Protesters have hurled petrol bombs at two armoured personnel carriers moving towards Independence Square, Reuters reports.
21:31:
President Yanukovych plans to make an address to the nation, according to pro-government MP Hanna Herman. She said there have been some meetings with the opposition but didn't give any details.
Nataliya Gumenyuk
tweets: stones, molotov cocktails are used by police as well. city is shut down, but people are ready to come. president silent. waiting for more
Christopher Miller
tweets: Much of city lights out in #Kyiv. Most of Maidan closed off by barricades. Lurking in only open side streets are titushki. Very dangerous.
5 Channel's Myroslava Petsa
tweets: Street light outage in central #Kyiv. Police shoot at #Euromaidan protesters with UV paint, making them easy targets in darkness
22:12:
Oksana Zinovieva, spokeswoman for Vitali Klitschko, says Mr Klitschko and Mr Yatsenyuk are still waiting to meet the president after almost an hour.
22:20:
Riot police have tried to charge into Independence Square but protesters resisted, according to reports.
22:21: max seddon
tweets: Multiple reports of explosions, gunshots at Maidan, renewed police attack on Kiev protesters
22:22:
Ukraine's Hromadske TV has aired live pictures of protesters escorting a captured riot policeman to Maidan's main stage.
Myroslava Petsa
tweets: Protesters capture a Berkut policeman. Man on #Euromaidan stage asks protesters to treat the captured with respect and dignity
22:37:
Former Ukrainian Foreign Minister Volodymyr Ohryzko has made an impassioned appeal for the US and EU to support the opposition, declaring that "'the policy of non-interference' of the EU and the US feels like an obvious betrayal", and warning that if they do not, they face "a real collapse of the European dream and a new terrifying East Asian Empire that will eventually swallow you". Calling for sanctions against those responsible, he demands to know, "What is now the price of the 'European dream'? Or should one ask Kremlin?"
Kyiv Post's Christopher Miller
tweets: Confirmed: Riot police on 6th floor of Trade Unions bldg. Got inside through 2nd floor window.
Maxim Tucker
tweets: The #Kiev trade union building, #euromaidan /opposition HQ for months, is now burning. Is #Ukraine 's government fighting fire with fire?
23:11:
The Ukrainian Health Ministry says that 221 people have required medical assistance and 114 have been taken to hospital in Kiev on Tuesday, says BBC Monitoring.
23:25:
Ukraine's Hromadske TV is showing dramatic pictures of people being rescued from the burning trade union building in Kiev's Independence Square.
23:26:
Ukraine's interior ministry says on their website that seven police officers have been killed.
23:43:
One of Ukraine's main protest leaders, Oleksandr Turchynov, says he was hit in the face by shrapnel while standing on the Maidan stage.
Kateryna Kruk,
tweets: boy has saved girl from house of trade unions, climbed a wall to get to her, ppl are shouting hero to him
23:45:
As flames engulf the trades union building, one of the last remaining opposition strongholds in the square, protest leaders on stage call on demonstrators to find groundsheets to help catch anyone who might have to jump from the building.
Maxim Eristavi,
tweets: Suddenly I'm cut off from Independence Sq.A line of what seems like riot-policemen on the way to the sq, shoot ppl who are trying 2 approach
23:51:
The head of the medical team in the protesters' main camp says 20 demonstrators have died during the day, according to Ukrainian Truth news website.
Christopher Miller,
tweets: Some protesters forced to jump from several floors up in Trade Unions bldg to safety. Protesters caught them using tents. #euromaidan
Moscow Correspondent for the Telegraph,
tweets: Watching people trying to punch their way out of top floor windows of burning protest hq trade union house. Horrific
00:25:
Vitaly Klitschko says opposition leaders have failed to reach agreement during talks with Mr Yanukovych. The president only called for protesters to leave the Maidan, Mr Klitschko is quoted as saying by Ukraine's Hromadske TV.
00:54:
A number of injured people during clashes are being treated in St Michael's Cathedral. Several dead bodies are also inside. The gold-domed cathedral famously rang its bells to call Kievites to defend the Maidan when the riot police tried to clear the camp last month.
01:08:
Fires continue to burn late into the night on the perimeter of the main protest camp in Kiev, the Maidan.
Ilya, in Kiev,
emails: It is just very bad! My friends and I want to live in a good country but the government doesn't want this, they have forgotten about the people and that is why they were elected. It is very sad for our country.
01:38:
Activists say big crowds of supporters are heading from western Ukraine and will join the protesters at Kiev's Maidan within hours.
01:47:
Two traffic officers have been shot dead by unknown gunmen in Kiev, the interior ministry says. It says another was seriously injured.
Maxim Eristavi, in Kiev,
tweets: The neighborhood around Independence Sq is patrolled by pro-govt thugs, I hear gun-shots time to time. That's a safari on protesters
02:02:
Dramatic pictures have emerged showing how some trapped activists climbed down from a burning building adjacent to the Maidan.
SOS Maidan website
tweets: "Maidan needs food. Simple and nutritious."
02:36:
More protesters' tents are burning now on the Maidan, amid reports that the police are launching a new assault.
Maxim Eristavi,
tweets: It's past 4AM in the Kyiv, the Independence Sq is still burning, clashes are on for almost 20 hours now
02:48:
The reported renewed police assault (see 02:36 entry) began shortly after 04:00 local time (02:00 GMT).
Arseniy Yatseniuk, opposition Fartherland party,
tweets: "Yanukovych has offered us actually to surrender. But people have the right to stand on the Maidan, and we will stand with the people."
03:39:
Ukraine's "We are Europeans" movement urges the country's Olympians at the Winter Games in Sochi, Russia, to stop competing to show solidarity with the protesters, Radio Liberty reports.
Euromaidan PR,
tweets: Near Instytutska Street militia and Berkut look very sleepy. Some of them are sleeping straight on the streets |PR News #Euromaidan #Kyiv
Paul, from Lviv,
emails: The government in our country keeps functioning mostly on an atmosphere of fear, special forces (paid thugs) and money from Putin.
05:15:
Ukrainian journalist Vyacheslav Veremiy has died in hospital after being beaten and shot by unknown attackers in Kiev, his colleagues say.
05:25:
This is one of the first morning pictures of the Maidan after the fierce overnight clashes.
Ihor Oleksiv, in Lviv,
emails: No more Yanukovich power in the city of Lviv. State administration, prosecutor's office, regional militia office are occupied by the protesters.
06:41:
Health ministry says that 241 people have been hospitalised, including 79 policemen and five journalists.
07:23:
A wall of smoke and flames rose into the dawn sky as the encampment of the protesters continued to burn, AFP reports, while lines of police and protesters - both clutching shields and wearing helmets and body armour - face off in an apocalyptic scene.
07:30:
Protesters, many of them masked and in battle fatigues, are pouring into Independent Square from different directions and preparing to take on police for a second straight day, Reuters says.
07:30:
The unrest has spread to at least three cities in the western part of the country, Reuters reports, quoting police sources. Protesters are reported to have seized the regional administration headquarters in the cities of Ivano-Frankivsk and Lviv in addition to torching the main police station in the city of Ternopil.
07:45:
As priests intoned prayers from a stage on the part of the square still held by protesters, young men in hard-hats are constructing elbow and knee pads. Others were pouring inflammable liquid into bottles - apparently to be used as petrol bombs.
Viktor in Kiev
emails: We really need HELP here, it is unbelievable that people whose major duty is to protect people, beat them up instead. Police officers have rules, that they MUST follow, despite the hatred they feel towards people. Instead, they get awarded for beating and torturing people in many ways.
08:20:
The Trades Union building is pretty much gutted by fire. So no opposition HQ any more, The BBC's Daniel Sandford Tweets
08:42: Michael in Kiev,
emails: from an insider's point of view, I can tell you that there is no divide, just the government who are thugs, trying to stay in power by all means. They have no ideology behind them, no support, just slaves and mercenaries.
08:45:
Tuesday was Ukraine's worst day of violence in 70 years
10:38: Kateryna Kruk in Kiev
tweets: "God is with us, yes, God and truth are with us, that's why we'll survive and will win!"
10:47:
Acting Ukraine Defence Minister Pavlo Lebedyev tells the Leviy Bereg website that airborne troops have been sent from Dnipropetrovsk to Kiev "to reinforce the guarding of the bases where weapons are kept, as well as the arms depots".
10:49:
Protesters in western Ukraine have seized the Trans-Carpathian region regional administration, according to the UNIAN news agency
10:51:
Two Ukrainian female skiers have failed to appear for their semi-final at the Sochi Olympics today, the Ukrainian news agency UNIAN reports. Marina Lisogor and Katerina Serdyuk were due to compete in the women's cross-country skiing Team Sprint Classic semi-finals.
11:16: BBC Correspondent, Duncan Crawford,
reporting live from Kiev he said the plumes of black smoke rising in Independence Square had been caused by tyres that had been set alight. He described the area as a "battle-zone" and said that there were "clashes still taking place sporadically" and that there was "no sign these clashes will die down".
11:18:
Ukraine, a sprawling nation of 46 million people with an ailing economy and endemic corruption has become the object of a geopolitical tug-of-war between Moscow and the West, Reuters comments. "That was played out in hand-to-hand fighting through the night, lit by blazing barricades on Kiev's Independence Square."
Kurt, Kiev
emails: As an American in Kiev, ordinary Ukrainians are angry as opposition seem to push the current government too far initiating violence for unmet demands causing disruption in daily life in Kiev (whole metro system closed).
11:39:
Polish border guard service says Ukrainian opposition protesters are blocking access at the border crossing between the village of Korczowa in Poland and Ukraine, Reuters has reported.
11:51:
Anti-government protesters have broken into the police headquarters in the main city in western Ukraine, Lvov, the Ukrainian news agency UNIAN reports. Activists told the agency that they had released all prisoners held in the building. The police are apparently not intervening and are removing technical equipment. In Ivano-Frankivsk, south of Lvov, protesters have seized the regional police directorate, the headquarters of the security service and the prosecutor's office, according to UNIAN.
12:19: Statement from Ukraine Olympic athletes
posted on their national Olympic committee website: "We are shocked by the events that occurred yesterday in Kiev.
"We are thinking about our families and loved ones back home in Ukraine, and we are doing our best to honour them on the fields of play here in Sochi. "We also deeply mourn and express our sincere condolences on the death of our fellow Ukrainians."
12:51:
UPDATE: A total of 263 protesters and 342 police officers are currently in hospital, most of them with gunshot wounds, Ukraine's acting Health Minister Rayusa Bohatyryova says, according to Interfax-Ukraine news agency - BBC Monitoring
Philip Larmett in Kiev
emails: Kiev is a city under siege. The main roads into the city are all blocked at strategic points. Traffic in the city is being diverted around the centre. The metro has not been operating since 5pm yesterday, when the police assault on the protestors began. Lviv, Ternopil and other regional capitals have joined the uprising. Many government buildings and police stations have been occupied. The whole of western Ukraine is no longer under control.
13:02: BREAKING:
Three people wounded as security forces open fire at protesters outside the Security Service building in Khmelnytskyy, western Ukraine, Den newspaper website reports. One of them, a middle-aged woman, reportedly died in hospital, says local website Ye.ua - BBC Monitoring.
13:38: Max Seddon
tweets: Ukrainian opposition HQ says a fresh police attack on Maidan is planned for 6 p.m.