KIEV, Ukraine — Police clashed with protesters and tore down their tents in the main square of the Ukrainian capital early Wednesday in an escalation of a weeks-long standoff threatening the leadership of President Viktor Yanukovych.

Hundreds of police in riot gear moved on the camp at Independence Square, dismantling barricades and pushing demonstrators who fought back. Scuffles broke out between police and opposition lawmakers who arrived to defend the camp.

Several thousand protesters shouted “Shame!” and “We will stand,” and sang the Ukrainian national anthem. An Orthodox priest read prayers.

Several protesters were injured. Some policemen helped injured activists up from the ground and moved them away.

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 EU – a pact that surveys showed was supported by nearly half the country’s people. The agreement would make Ukraine more Western-oriented and would be a significant loss of face for Russia, which has either controlled or heavily influenced Ukraine for centuries.

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.