The political party of jailed Ukrainian opposition leader Yulia Tymoshenko says riot police stormed its headquarters in the capital, Kyiv, on Monday as police begin to dismantle barricades set up by anti-government demonstrators at a central square.
An opposition spokeswoman says troops entered the central headquarters of the Fatherland party Monday evening, breaking down doors and seizing computer equipment. The Kyiv police deny the claim.
The allegations came as hundreds of police, in full riot gear, took up positions across the capital including the city's Independence Square, the focal point of the demonstrations.
Riot police began dismantling barricades erected outside of some government buildings by demonstrators.
Protesters were under a court-ordered deadline to disperse from the city offices or face ejection. No clashes were reported.
Ukrainian opposition leader Vitaliy Klitschko called on police to restrain from using force, describing the situation as being 'stretched like a string" and capable of switching toward either side.
"We are calling upon the law enforcement to restrain from using force against peaceful demonstrators. The result of this can be upsetting, not just regarding the beating of protesters, but resulting disturbance within all of society."
Opposition leader Arseniy Yatsenyuk said he hoped police would allow food and emergency services to get through to protesters camped in Independence Square.
"Right now the police major promised to open a corridor. If not, it will be bad".
The European Union has called for the Ukrainian government to show restraint, saying Europe has "the right and the duty" to support protesters.
The deployment of riot police came as Mr. Yanukovych agreed to talks with three former Ukrainian presidents in an effort to defuse the crisis over his refusal to sign a long-anticipated EU trade deal in favor of closer ties to Russia.
Russia has exerted strong economic pressure on cash-strapped Kyiv to discourage the EU deal. Russia is Ukraine's largest foreign investor, trading partner and chief natural gas supplier.
Moscow is seeking to form a trade bloc of former Soviet republics and satellite countries. Earlier this year, it imposed restrictions on goods from Ukraine, cutting Ukrainian exports 25 percent and dragging the country into recession.