Police storm protest camp in Ukraine

Eite Berkut anti-riot police and interior ministry special forces moved against the protestors at around 2:00 am (midnight GMT) in a move that prompted US Secretary of State John Kerry to express "disgust" over the crackdown.

But the protesters, angry at President Viktor Yanukovych's rejection of an EU pact under Russian pressure, stayed on in part of the huge square and their numbers swelled to at least 10,000 after the police action.

Dozens formed human walls to prevent more riot police from entering the square from adjoining roads, an AFP correspondent. Speakers gave addresses from the stage as Ukrainian pop anthems made famous during the 2004 Orange Revolution blared through loudspeakers.

Thousands of anti-riot police had earlier surrounded the square and then entered the area, using their sheer numbers to force the demonstrators away from the road running through the square

The police also smashed down the barricades that the protesters had put up around the square and ripped down several of their tents.

'Spitting in the face'

Ukrainian opposition leader Arseniy Yatsenyuk called for a millions-strong protest in Kiev after the police actions, predicting that the regime of Yanukovych would fall.

"We will not forgive this. Here there will be millions and his regime is going to collapse," Yatsenyuk, the leader of the party of jailed ex-premier Yulia Tymoshenko, told the protesters on Independence Square.

"Yanukovych spat in the face of the United States and the EU member states," he said as protesters chanted "out with the gang!".

Thousands of protesters had been defying sub-freezing temperatures to remain overnight on the square in protests that started almost three weeks ago.

"Kievans rise up! Only together can we win our right to live in a free country," world boxing champion and leader of the UDAR (Punch) opposition party Vitali Klitshcko told the protesters.

Police at the scene said their aim was not to disperse the entire protest but to free up Kiev's main Khreshchatyk Street -- that passes through the middle of the square -- for traffic.

"Police are working in cooperation with the Kiev municipal services to remove the barricades blocking the passage," a Kiev police spokesperson told AFP.

The leader of the nationalist Svoboda (Freedom) movement Oleg Tyagnybok said that several protesters had been injured and the authorities had detained 11 people.

Ashton in Kiev, EU concerned

The police action came as top diplomats from the EU and United States were in Kiev in a bid to resolve the standoff and hours after Yanukovych had held talks with EU foreign policy chief Catherine Ashton.

In an angry reaction, Kerry said Washington "expresses its disgust with the decision of Ukrainian authorities to meet the peaceful protest... with riot police, bulldozers, and batons, rather than with respect for democratic rights and human dignity."

"This response is neither acceptable nor does it befit a democracy," he added.

The EU's delegation in Kiev said it was seeking to contact Ukrainian authorities to prevent the use of violence against citizens.

"The authorities didn't need to act under the cover of night," Ashton said in a statement.

In a sign of Europe's support for the demonstrators, Ashton late Tuesday personally visited the epicentre of the protests on Independence Square, known locally as the Maidan.

"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.

US Assistant Secretary of State Victoria Nuland was also in Kiev and expected to hold talks with Yanukovych.

Yanukovych on Tuesday convened Ukraine's ex-leaders Leonid Kuchma, Leonid Kravchuk and Viktor Yushchenko for an unprecedented crisis 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.

"Civil society is now awaiting a signal from the president," said Kuchma, Ukraine's president between 1994 and 2004.