Ukrainian security forces have stormed Kiev's Independence Square, occupying the area protesters had held for more than a week and ripping down their tents.
Thousands of Berkut anti-riot police surrounded the square early on Wednesday and then entered the area, using their sheer numbers to force the demonstrators away, an AFP correspondent said.
The police also smashed down the barricades that the protesters had put up around the square.
Thousands of protesters had been defying sub-freezing temperatures to protest President Viktor Yanukovych's rejection of an EU pact. The protests started almost three weeks ago.
The move came as top diplomats from the EU and US were in Kiev in a bid to resolve the stand-off.
There was no sign of any violence, but security forces herded the thousands of protesters who had remained on the square into two separate groups, the correspondent said.
Protesters urged each other through the loudspeaker system not to use violence against the security forces on Independence Square, known as the Maidan in Kiev.
"We follow events in and around Maidan at this moment with great concern. Repression is not way forward for Ukraine - reform should be," Swedish Foreign Minister Carl Bildt wrote on Twitter in one of the first international reactions.
Yanukovych had on Tuesday accused the pro-European opposition of posing a threat to national security.
The storming of the Maidan came after the president held talks on Tuesday with EU foreign policy chief Catherine Ashton and his three predecessors in Kiev.
"Substantial meeting (with) President Yanukovych, all relevant issues discussed," Ashton's spokeswoman Maja Kocijancic added on Twitter, saying the talks lasted three and a half hours, but giving no further details.
In a sign of Europe's support for the demonstrators, Ashton later personally visited the square, an AFP correspondent said.
Arm-in-arm with opposition leader Arseniy Yatsenyuk, who gave her a guided tour of the protest camp, Ashton was given a rousing welcome by the protesters who chanted "Europe!" in unison.
US Assistant Secretary of State Victoria Nuland was also in Kiev and expected to hold talks with Yanukovych.
Yanukovych had earlier convened with Ukraine's ex-leaders Leonid Kuchma, Leonid Kravchuk and Viktor Yushchenko for an unprecedented meeting at the presidential administration.
"Calls for a revolution pose a threat to national security," Yanukovych said in comments broadcast on national television. "I want that this dark page is turned and is never allowed to happen again."
Yanukovych's decision to scrap key trade and political agreements with the EU and police violence against protesters have plunged the ex-Soviet country into its most acute political crisis since the Orange Revolution in 2004.
