Opposition leaders held crisis talks with Yanukovych on Wednesday, but left the meeting saying he had not provided any clear answers to their political demands.

"You, Mr. President, have the opportunity to resolve this issue. Early elections will change the situation without bloodshed and we will do everything to achieve that," former boxer turned opposition leader Vitali Klitschko told a gathering of some 40,000 people in Kyiv's Independence Square late in the day.

Ukraine's two-month long political crisis, which began after the government rejected a pact with the European Union in favor of boosting ties with Russia, has escalated to new levels of violence. At least two protesters were killed in fiery clashes with security forces in Kyiv on Wednesday.

The opposition has demanded Yanukovych's government step down and end the recently-passed legislation that seeks to limit protests. Klitschko told the crowd that the opposition would "go on the offensive" if the president doesn't quickly offer compromises.

"If Yanukovych does not make concessions, then tomorrow [Thursday] we will go on the attack," he said

Another opposition leader, Arseniy Yatsenyuk, echoed Klitschko's demand, warning that if the president doesn't concede, "tomorrow we will go forward together. And if it's a bullet in the forehead, then it's a bullet in the forehead, but in an honest, fair and brave way."

Bloodshed in Kyiv

The focus of Wednesday's clashes was Grushevsky Street in the city center. A police assault against demonstrators there launched in the morning sparked the clashes.

After initially being pushed out, the protesters regrouped, setting up barricades and lighting tire fires. Demonstrators threw stones and Molotov cocktails, and the police responded with tear gas, stun grenades and rubber bullets.

At least two people died in the violence from gunshot wounds, though it is unclear whether they were killed by live fire rounds or rubber bullets. The opposition put the number of deaths at five.

Hundreds of other people were injured in the clashes, and the Interior Ministry said at least 70 demonstrators were arrested.

International community reacts

European leaders have spoken out against the escalation in violence and warned of consequences.

Speaking from a summit in Montreaux, Switzerland, German Foreign Minister Frank-Walter Steinmeier said "violence is not the answer, not in Ukraine not for either side."

"We have made clear to President Yanukovych that we cannot condone a violent response by the government in Ukraine which simply widens and worsens the suffering for more and more people," he added.

EU foreign policy chief Catherine Ashton issued a strong condemnation, saying "the reported deaths of several protesters is a source of extreme worry and my sympathy goes to all those affected."

European Commission President Jose Manuel Barroso said the violence could result in "action" being taken by the EU against Ukraine, but did not elaborate on what form this might take.

The United States has imposed visa restrictions on Ukrainian officials who were reportedly involved in police action against protesters in November and December.

dr/ccp (AP, AFP, dpa, Reuters)