Ukraine's President Viktor Yanukovich is set to return to work on Monday after a period of sick leave, a statement on the presidential website said. Thousands of anti-government protesters have gathered in central Kiev to demand his resignation.
Ukrainian protesters shouted "Murderers" and "Glory to Ukraine" at police following reports that a man had been shot dead by a police sniper and that another demonstrator had fallen to his death during violent clashes.
The latest clashes broke out as riot police, using teargas, dismantled barricades in European Square in Kiev.
Retreating protesters hurled homemade petrol bombs at police, eyewitnesses claims.
Ukraine has experienced difficult days before but few have been so complex or so pivotal.
The Ukrainian government says it is is ready to use all tools available to restore order if violence and unrest continues.
These are difficult days for Ukraine, a country edging toward its second revolution in a decade.