Demonstrators on the capital's Independence Square - or Maidan - on Thursday threw Molotov cocktails and rocks at riot police, who responded with rubber bullets, stun grenades and tear gas.

Shortly before the fresh fighting, Ukraine's Health Ministry had raised its death toll from clashes until Wednesday to 28 killed, with 287 still hospitalized. That toll reportedly rose on Thursday, with news agencies saying their correspondents had seen more bodies on the square and in the near vicinity. One agency put Thursday's figure as high as 25.

The flare-up in violence came just hours after Wednesday's truce agreement between Ukraine President Yanukovych and opposition leaders Vitali Klitschko, Arseniy Yatseniuk and far-right nationalist Oleh Tyahnibok. Included was a pledge to start negotiations "aimed at ending the bloodshed [and] stabilizing the situation in the country," according to a statement posted on the presidential website.

On Thursday, Klitschko issued a statement on his website saying: "The resumption of clashes on the Maidan [Independence Square] at a time when a truce was called is a planned provocation by the authorities against peaceful protesters."

EU foreign ministes to visit Kyiv

Yanukovych had been set to meet with visiting foreign ministers from Germany, France and Poland on Thursday to discuss the turmoil. The foreign ministers were then expected to head to an emergency European Union meeting in Brussels.

That meeting was put in doubt as the fresh violence erupted, and the venue was changed. Shortly before 1000 CET (900 UTC), Poland's Foreign Minister Radoslaw Sikorski wrote on Twitter: "Black smoke, denotations and gunfire around presidential palace. Meeting moved to another location. Officials panicky."

Fiercest since November

Clashes had began on Tuesday when protestors attacked police lines and lit fires outside parliament. In response, riot police attempted to break up the protestors' camp on the Maidan square. Burning barricades were erected by protestors as they attempted to hold their ground against police.

The violence was the fiercest seen since the camp was erected by anti-government demonstrators in November, after Yanukovych's decision to walk away from an EU association act in favor of closer ties with Russia.

On Wednesday at a joint press conference in Paris, German Chancellor Angela Merkel and France President Francois Hollande called for sanctions against Ukraine's leadership.

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