Kiev (AFP) - Pro-EU Ukrainian demonstrators dug in on Wednesday night as domestic and international pressure mounted on President Viktor Yanukovych to end a three-week standoff over his refusal to sign an EU deal.
The demonstrators had earlier forced riot police to retreat after a pre-dawn raid on their protest camp, in a blow to the authority of Yanukovych who called for talks.
EU foreign policy chief Catherine Ashton met with Yanukovych twice over the past two days and US Assistant Secretary of State Victoria Nuland told the president the attempted police crackdown was "inadmissable".
In Washington, the State Department said the United States was considering "a range of options" to respond to Ukraine's protest crackdown, including possible sanctions.
Yanukovych vowed late Wednesday that the authorities would never use force against peaceful protests and urged the opposition to sit down for talks.
"For the sake of achieving compromise I am calling on the opposition not to reject (talks), not to follow the path of confrontation and ultimatums," Yanukovych said in a statement.
"I am ready to participate in such roundtable talks personally."
The opposition, which has previously ruled out any negotiations until he dismissed the government and punished riot police for crushing a smaller protest on November 30, vowed to do everything to topple the president.
Jailed former prime minister Yulia Tymoshenko warned the protest movement against holding any negotiations with Yanukovych.
"I am calling on all Ukrainians: rise up!" Yanukovych's arch rival said in a statement on Wednesday. "No talks with the gang."
Several dozen people were injured in the early hours when riot police and interior ministry special forces moved against the demonstrators who have occupied Kiev's Independence Square in anger at the rejection of a landmark EU pact.
The security forces tore down makeshift barricades but were eventually forced into a humiliating retreat amid cheers from the demonstrators after the ranks of protesters swelled.
"We have not won the war yet but we've decisively won this battle. The authorities are panicking," said protester Anton Kulyk.
The early morning police action -- which came as both Nuland and Ashton were in Kiev -- sparked unprecedented international criticism of Yanukovych, with US Secretary of State John Kerry expressing "disgust" at the crackdown.
An estimated 5,000 pro-EU demonstrators were camping out in Independence Square on Wednesday night, reinforcing barricades with snow and sand bags.
Warning of full-scale conflict
The spiralling crisis risks pitting the Ukrainian-speaking, pro-EU west of the country against the Russian-speaking, largely pro-Yanukovych east.
The powerful Ukrainian Orthodox Patriarch Filaret warned Wednesday that continued violence could "slide into a full-scale civil conflict".
In a sign of the protests' growing impact, an emergency session by a local legislature in the western city of Ternopil condemned "an escalation of violence" and said city lawmakers would no longer implement the "criminal orders" from Yanukovych and his government.
Wednesday's police crackdown came just hours after three former Ukrainian presidents Leonid Kuchma, Leonid Kravchuk and Viktor Yushchenko called on Yanukovych to protect the rights of protesters.
The demonstrators managed thwart a bid by security forces to retake Kiev city hall, which has been occupied by some 200 opposition activists for over a week.
Police outside the building used truncheons to beat demonstrators, who responded with sticks. Activists in the upper storeys of the building doused officers with freezing water from a fire hose, forcing them to leave.
City authorities said 30 people sought medical help and half of them were hospitalised.
'We care about your future'
Yanukovych's decision to scrap the key trade and political agreements with the EU, coupled with police violence against protesters, have plunged the ex-Soviet country into its most acute political crisis since the 2004 pro-democracy Orange Revolution.
EU foreign affairs head Ashton said she was "deeply concerned about last night's action taken by riot police", which came just hours after she held talks with Yanukovych.
"We will stay engaged because we care very much about your future," she told reporters after meeting the president again on Wednesday.
Ukraine's Deputy Premier Serhiy Arbuzov will meet EU Enlargement Commissioner Stefan Fuele in Brussels on Thursday to discuss the association accord, the commissioner's spokesman Peter Stano said.
US diplomat Nuland, who also met with Yanukovych on Wednesday, stressed there was still a way for the ex-Soviet country to become part of Europe.
Prime Minister Mykola Azarov said that cash-strapped Ukraine needed a 20-billion-euro ($27.5-billion) loan from the EU before it signs the association pact.
With tensions rising, opposition leader Vitali Klitschko cancelled a planned trip to Paris and instead discussed the crisis with French Foreign Minister Laurent Fabius by phone.