Pro-European Union activists guard the barricade during clashes with riot police in Independence Square in Kiev, Ukraine, Wednesday, Dec. 11, 2013. 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. (AP Photo/Efrem Lukatsky)

KIEV, Ukraine - The withdrawal of riot police from two areas in the Ukrainian capital is raising opposition hopes that three weeks of escalating protests have begun to erode police support for President Viktor Yanukovych and his government.

Yuri Lutsenko, a former Interior Minister who is now an opposition leader, declared that the police retreat early Wednesday shows that "basically only some units remain at the service of the regime."

"This is a great victory," Arseniy Yatsenyuk, leader of the largest opposition party in parliament, said from the stage at Kyiv's central Independence Square, where protesters have set up an extensive protest tent camp manned around the clock.

"I want to calm everyone down — there will be no dispersal" of protesters," the current Interior Minister, Vitaly Zakharchenko, said in a statement.

However, his statement did not explain why thousands of helmeted and shield-bearing police were deployed in the first place.

The manoeuvrs took place as Western diplomats increased their pressure on Yanukovych to seek a solution to the tensions that have paralyzed this economically troubled nation of 46 million. Protesters want Yanukovych dismiss the government, appoint a new one committed to signing an accord with the EU, release all the arrested protesters and punish the police who beat peaceful demonstrators.

Assistant U.S. Secretary of State Victoria Nuland met with Yanukovych on Wednesday after visiting the protest camp.

"I made it absolutely clear that what happened last night, what is happening in security terms here, is absolutely impermissible in a European state, a democratic state," she said after the talks, standing a few yards away from buses that were blocking the street to the presidential administration building in Kyiv, the capital.

It was Yanukovych's shelving in November of an agreement with the European Union to deepen economic and political ties that set off the protests. Supporters of the pact want Ukraine to become closer to Western Europe and distance itself from Russia, which ruled or dominated Ukraine for centuries.

EU foreign policy chief Catherine Ashton was also in Kyiv to meet both government officials and opposition figures to urge them toward holding talks, which so far has appeared to be a distant prospect.

The police action began about 1 a.m. when phalanxes approached Independence Square from several directions, tearing down some of the tents and barricades erected by protesters and scuffling with some.

Many of the protesters, wearing orange construction hats to protect themselves from police truncheons, locked arms against the police and simultaneously jumped up and down to stay warm in freezing temperatures that plunged to 12 degrees Fahrenheit (minus 11 Celsius).

Scuffles broke out between police and opposition lawmakers, one of whom lay down on the snow to block a vehicle from advancing on the camp. One Orthodox priest sang prayers, and a popular Ukrainian rock song with the lyrics "I will not give up without a fight" blared from loudspeakers. Pop singer Ruslana sang the national anthem from a stage.

Separately, three buses of riot police parked on the steps of the city administration building, about 300 metres (yards) away from the square occupied by protesters.

The protesters poured water on the steps, which quickly froze, and grappled with police. The police returned to the buses and they pulled away hours later, followed by protesters who shouted "Shame!" and "Way to go!"

The far larger police contingent at the square also pulled away.

By Wednesday afternoon, new tents and barricades were being put up to replace those destroyed overnight.

The protests are the biggest since Ukraine's pro-democracy Orange Revolution in 2004, which forced the annulment of Yanukovych's victory in a fraud-tainted presidential election and ushered his pro-Western opponents into power.

Yanukovych won back the presidency in the 2010 vote, narrowly defeating Yulia Tymoshenko, a key Orange Revolution figure who had become prime minister. After losing to Yanukovych, she was imprisoned on charges of abuse of office, a case widely criticized in the West as political revenge.

___

Yuras Karmanau in Kyiv and Laura Mills in Moscow contributed to this report.

_____

Follow Danilova at https://twitter.com/mashadanilova and Heintz at https://twitter.com/jeheintz.

News from © The Associated Press, 2013