Clashes erupted between security forces and demonstrators in Kyiv on Tuesday night after a 6 p.m. (1600 UTC) deadline for demonstrators to halt protest action expired.

Protesters hurled petrol bombs at police, setting parts of the protest site on fire. Security forces responded with water canon and stun grenades.

Earlier in the afternoon, the Interior Ministry had issued a statement warning people on Kyiv's Independence Square to clear out or "we will be forced to restore order with all legal means," the Interior Ministry had said.

Heavyweight boxing champion-turned-politician Vitali Klitschko urged women and children to leave the capital city's Independence Square - known as Maidan - as the opposition could not "rule out the possibility that [police] will storm [the camp there]."

The government's ultimatum was issued as security forces began moving through Maidan following a mass march of some 20,000 people on the parliament building earlier in the day. Security forces reportedly had begun pushing through barricades to begin clearing out dissidents.

There were also reports of up to nine fatalities on Tuesday, among them, two policemen, according to Ukrainian authorities.

A parliamentarian cited by news agency Reuters had said earlier in the afternoon that the bodies of three protesters had been brought away from the crowd into a government building. The deceased had apparently sustained gunshot wounds.

Kyiv's subway system had been temporarily shut down in the wake of the violence.

Plumes of smoke rose over central Kyiv on Tuesday as tensions escalated between anti-government demonstrators and security forces. Police began firing tear gas at masses of people marching from Maidan to the parliament building after some protesters began throwing rocks at the security forces. They also set several police vans on fire. Dozens were injured in the clashes.

Government opponents have been calling for the resignation of President Viktor Yanukovych since November, when he shelved an association act with the EU in favor of a multi-billion-euro loan from Moscow. The move sparked mass protests, primarily in the capital city.

International community condemns violence

The EU was joined by the US and NATO in calls for the Ukrainian government to restore order and end the political crisis.

EU foreign policy chief Catherine Ashton called on the Ukrainian government to find a solution to the crisis.

"I am deeply worried about the grave new escalation in Kyiv," Ashton said in a statement. "I condemn all use of violence, including against public or party buildings."

Washington and NATO expressed concern, with NATO chief Fogh Rasmussen urging all parties to "resume dialogue."

German Foreign Minister Frank-Walter Steinmeier also called on Ukraine to refrain from using force after speaking with his Ukrainian counterpart Leonid Koschara on Tuesdaay.

"A return to violence in Ukraine is most assuredly not the way to reach an equilibrium and [to ensure a stable] future for the country," he added.

The call came a day after Ukrainian opposition leaders Vitali Klitschko and Arseniy Yatsenyuk met with German Chancellor Angela Merkel and Foreign Minister Frank-Walter Steinmeier in Berlin. Although Merkel said she sympathized with the will of the Ukrainian people and would provide support for a positive outcome to end the political crisis, she said she would not support sanctions against the Ukrainian government.

kms/ph (AP, AFP, Reuters, dpa)