KIEV, Ukraine (AP) -- Security forces clashed with protesters as they began tearing down opposition barricades and tents set up in the center of the Ukrainian capital early Wednesday, in an escalation of the weeks-long standoff threatening the leadership of President Viktor Yanukovych.
Several thousand police in riot gear used their shields to push back protesters and successfully removed some of the tents and barricades. But thousands of protesters, their ranks swelling through the night, put up fierce resistance for hours, shoving back at the police lines to keep them away from the center of the protest camp on Independence Square in downtown Kiev.
The protests began in late November when Yanukovych backed away from a pact that would deepen the former Soviet republic's economic ties with the 28-nation European Union -- a pact that surveys showed was supported by nearly half the country's people. The agreement would make Ukraine more Western-oriented and represent a significant loss of face for Russia, which has either controlled or heavily influenced Ukraine for centuries.
Demonstrators, waving EU and Ukrainian flags and singing the national anthem, shouted "Shame! Shame!" and "We will stand." Scuffles broke out between police and opposition lawmakers, one of whom laid down on the snow trying to block a vehicle from advancing on the camp. An Orthodox priest sang prayers, and one protester undressed to his waist in the frigid air, got down on his knees and shouted "Stop this ... We are one people!"
Several protesters were injured. Some policemen helped injured activists up from the ground and moved them away. The Interior Ministry said 10 policemen also sustained injuries in the scuffle.
After some of the barricades and tents were dismantled, police and city workers began to remove debris with bulldozers.
Kiev police said authorities were merely trying to clear the streets leading to Independence Square, but not to remove the main encampment, the Ukrainian Interfax news agency reported. Meanwhile, scores of protesters remained barricaded inside the city hall building, which they had been occupying for weeks. They hosed the steps leading to the entrance with water so police would slip on the ice if they attempted to storm the building.
U.S. Secretary of State John Kerry issued a strong statement, expressing the United States' "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," said Kerry, urging authorities to show "utmost restraint" and protect human life. "As church bells ring tonight amidst the smoke in the streets of Kyiv, the United States stands with the people of Ukraine. They deserve better."
Opposition leader Vitali Klitschko, who is the reigning world heavyweight boxing champion, urged Ukrainians to rush to the center of the capital to defend democracy.
"We will say no to a police state, no to a dictatorship," he told protesters in the square.
Hundreds of people heeded his call, heading to Independence Square as Kiev residents organized on social networks to arrange carpools.
Another top opposition leader, Arseniy Yatsenyuk told protesters that Yanukovych "has spat in the face of America, EU countries and 46 millions of Ukrainians and we will not forgive that."
The confrontation at the protest camp unfolded as EU foreign policy chief Catherine Ashton and U.S. Assistant Secretary of State Victoria Nuland were in the city to try to talk to the government and the opposition and work out a solution to defuse the crisis.
"The authorities didn't need to act under the coverage of night to engage with the society by using police," Ashton said in a statement after the police action started. "Dialogue with political forces and society and use of arguments is always better than the argument of force."
The protests are the biggest in the former Soviet republic since Ukraine's pro-democracy Orange Revolution. Those protests, also centered on Independence Square, known as the Maidan, succeeded in forcing the annulment of Yanukovych's fraud-tainted presidential victory in 2004, and ushered his pro-Western opponents into power. Yanukovych returned to the presidency in the 2010 vote, drawing on support from heavily industrialized eastern Ukraine where there are many Russian speakers.
Aiming to defuse the latest crisis, Yanukovych had called earlier Tuesday for the release of the demonstrators previously arrested in the protests and vowed that Ukraine is still interested in integrating with Europe.
His efforts, however, stopped far short of opposition demands that his government resign, and the two sides appeared no closer to a resolution that would chart out a secure future for their economically troubled nation.