The capital’s police department said in a statement that three police officers died and 184 were injured, 35 of them critically. By late Tuesday, 159 officers have been admitted to city hospitals.
A Kiev police spokesman said that seven civilians also died as a result of the clashes. Two of them died of heart failure, one was killed in a car accident, one in fire and three were shot dead.
Fighting escalated in Kiev as a standoff played out inside parliament, where deputies faced off over changes to the constitution that the opposition has said could be a way out of the political paralysis gripping the country.
Thousands of radical demonstrators moving toward the parliament building around midday – many of them wielding shields and sticks, and wearing masks – were confronted by police who deployed rubber bullets, stun grenades and tear gas. Pictures from the front lines showed rioters ripping up cobblestones to hurl at police.
Riot police pushed the crowd back to barricades surrounding the central Independence Square. The area was cordoned off on Tuesday evening and police attempted to disperse the crowd using stun grenades and smoke pellets. At least one water cannon was also used.
Protesters responded by throwing Molotov cocktails and firecrackers at officers. Fires erupted in several areas.
A lawmaker with the ruling Party of Regions, Oleh Tsaryov, vowed shortly after that the Independence Square rally will be dispersed "in an hour.”
"We will restore order in Kiev and then will restore it around the country,” he said.
The crowd also seized the capital's city hall, which served as the headquarters of the major anti-government protest in Ukraine for nearly two months. The building was unblocked on Sunday after authorities freed all demonstrators who had been detained since the unrest erupted.
Kiev police said a group of young people, armed with truncheons, also attacked the Canadian Embassy where they "smashed property and attempted to hurt employees of the diplomatic mission.”
Police also said a truck, apparently hijacked by protesters, rammed a group of people, injuring three. The vehicle was later set on fire.
Lesya Orobets, a deputy with the opposition Batkivshchyna (Fatherland) party, said on her Facebook page that at least three protesters had been killed. Radio Free Europe cited opposition medic Olga Bogomolets as also saying from a first aid center near parliament that three people had been killed and seven were in a serious condition.
The Interior Ministry confirmed reports of six dead early Tuesday evening and said police were investigating the matter.
Police earlier said one person was killed at the headquarters of the ruling Party of Regions, which was stormed by demonstrators Tuesday.
Ukrainian officials said early Tuesday evening that if rioting did not die down within two hours – by 6 p.m. local time – authorities would be obliged to restore order by means provided for by law.
Operation of the Kiev metro was suspended amid the clashes, and passengers were told to disembark as the trains came to a halt across the city.
A Defense Ministry spokesperson said the seizure of a military building in the city earlier in the day by protestors would provoke an appropriate response by the military, according to the Russian state newspaper Rossiiskaya Gazeta.
Opposition deputies in parliament blocked the speaker’s rostrum Tuesday in protest against pro-government deputies’ refusal to register a bill introducing reform to the constitution.
The bill was eventually registered, the opposition Svoboda party said later Tuesday on Twitter.
Opposition forces are seeking the restoration of the 2004 constitution, which they say would ensure a way out of the political crisis by transferring more powers to parliament from the president.
A spokesperson for the country’s legislature said that none of the draft resolutions to restore the 2004 constitution submitted Tuesday for consideration by the body had met a requirement of 150 signatures to bring them to the floor.
The Party of Regions has said it is willing to review the law but has refused to automatically return to a previous version.
Moscow reiterated Tuesday that the worsening situation in downtown Kiev is a result of Western interference in the country’s politics, according to a statement by the Russian Foreign Ministry.
Large-scale street protests erupted in Kiev and other Ukrainian cities in November after President Viktor Yanukovych backed away from deals to deepen political and economic cooperation with the European Union and instead opted for closer ties with Russia.
The protests have sporadically descended into violence on both sides.
Yanukovych has said he is ready to appoint a coalition government that includes members of the opposition, the speaker of parliament said last week.