One camp commander, Oleh Mykhnyuk, told the AP that protesters threw firebombs at riot police on the square overnight. As the sun rose, police pulled back, protesters followed them and police then began shooting at them, he said.
The Interior Ministry warned Kiev residents to stay indoors Thursday because of the "armed and aggressive mood of the people."
Yanukovych claimed Thursday that police were not armed and "all measures to stop bloodshed and confrontation are being taken." But the Interior Ministry later contradicted that, saying law enforcers were armed as part of an "anti-terrorist" operation.
Some signs emerged that Yanukovych is losing loyalists. The chief of Kiev's city administration, Volodymyr Makeyenko, announced Thursday he was leaving Yanukovych's Party of Regions.
"We must be guided only by the interests of the people, this is our only chance to save people's lives," he said, adding he would continue to fulfill his duties as long as he had the people's trust.
Another influential member of the ruling party, Serhiy Tyhipko, said both Yanukovych and opposition leaders had "completely lost control of the situation."
"Their inaction is leading to the strengthening of opposition and human victims," the Interfax news agency reported.
The parliament building was evacuated Thursday because of fears that protesters would storm it, as were the government office in Kiev and the Foreign Ministry buildings. But parliament convened in the afternoon, with some pro-government lawmakers heeding the opposition's call to work out a solution to the political stalemate.
As the violence exploded Thursday morning and heavy smoke from burning barricades at the encampment belched into the sky, the foreign ministers of three EU countries — France, Germany and Poland — met with Yanukovych for five hours after speaking with the opposition leaders. The EU ministers then returned to speak again with opposition leaders.
Prior to the clashes Thursday, the Ukrainian Health Ministry said 28 people have died and 287 have been hospitalized this week. But protesters who have set up a medical facility in a downtown cathedral so that wounded colleagues would not be snatched away by police say the number of wounded is significantly higher — possibly double or triple that.
The Caritas Ukraine aid group praised the protest medics but said many of the wounded will need long-term care, including prosthetics.
The clashes this week have been the most deadly since protests kicked off in November after Yanukovych shelved an association agreement with the European Union in favor of closer ties with Russia. Russia then announced a $15 billion bailout for Ukraine.
In Moscow, President Vladimir Putin was sending former ombudsman Vladimir Lukin to Ukraine to act as a mediator.
Prime Minister Dmitry Medvedev said Russia will "try to do our best" to fulfill its financial obligations to Ukraine, but indicated Moscow would hold back on further bailout installments until the crisis is resolved.
"We need partners that are in good shape and a Ukrainian government that is legitimate and effective," he said.
At the Winter Olympics in Sochi, Ukrainian alpine skier Bogdana Matsotska, 24, said she will not take part in Friday's women's slalom due to the developments in Kiev.
"As a protest against lawless actions made toward protesters, the lack of responsibility from the side of the president and his lackey government, we refuse further performance at the 2014 Sochi Olympic Games," her father and coach, Oleg Matsotskyy, wrote in a Facebook post.
Maria Danilova, Jim Heintz and Yury Uvarov in Kiev contributed to this report. Zhukovskaya Twitter message at https://twitter.com/OlesyaZhukovska
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