Ukraine's opposition has threatened to march on President Viktor Yanukovych's presidential palace and seal him inside if he does not give in to their demands, the BBC reported Sunday.
Hundreds of thousands of people filled Kiev's Independence Square and the surrounding streets on Sunday, chanting "Ukraine is Europe!" and calling on Yanukovych to resign. The protest was the largest yet, in a two-week popular surge trying to force the president to reverse a decision to halt integration into the EU.
Addressing the crowds, opposition leaders said they were giving Yanukovych 48 hours to fire his prime minister, Mykola Azarov, or they would march on his residence outside Kiev and shut him in. Azarov survived a no-confidence vote in parliament on Tuesday and has called the protesters in the square "Nazis and criminals."
The protesters carried the yellow-and-blue flags of both Ukraine and the European Union.
One man wielded an effigy of the severed head of the late Libyan leader Muammar Gaddafi above a sign reading: "Vitya [Yanukovych], the game is over!"
"We do not want to be kept quiet by a policeman's truncheon," heavyweight boxer and opposition leader Vitali Klitschko told the crowd. "If this government does not want to fulfill the will of the people, then there will be no such government, there will be no such president. There will be a new government and a new president."
After months of pressure from Russia, Yanukovich suddenly stepped back last week from signing the deal on closer relations with the EU in favor of renewed economic dialogue with Moscow.
Far-right leader Oleh Tyahniboh called for a national strike, and members of his Svoboda (Freedom) party occupied Kiev's city hall along with followers of former economy minister Arseny Yatsenuk's Batkivshchyna (Fatherland) Party.
All three opposition leaders also occupied a trade union building, turning it into a temporary headquarters. On Friday, Kiev police said that if the two occupied buildings were not vacated within five days, they would be cleared with force.
There has been no violence in the protests since Sunday, when protesters attempted to storm the presidential administration and riot police responded with brutality.