Ukrainian police and protesters at a tent camp near the parliament building in Kyiv clashed on Saturday, with six demonstrators and four officers reported to have been injured.
Police said fire bombs, smoke bombs and grenades were found in the camp during their raid, and that some 50 people were detained after they offered resistance.
Andrey Kryshchenko, the head of Kyiv police, said officers had been carrying out an investigation connected with another clash on Tuesday in which 15 police were hurt.
Ukrainian media have reported that police had ordered the removal of the camp, which was set up by supporters of opposition leader Mikheil Saakashvili.
The protesters have been demanding that the country set up a national anti-corruption court.
Saakashvili, the former leader of Georgia, was deported from the country in February and stripped of Ukrainian citizenship.
Persona non grata
The opposition leader was once a close ally of Ukrainian President Petro Poroshenko, but has since become one of his most vocal critics. Kyiv accuses him of wanting to carry out a coup backed by allies of former Moscow-friendly President Viktor Yanukovych.
Saakashvili, who is now stateless after already losing his Georgian citizenship, has vehemently denied the charges and is living in exile in Poland.
tj/jlw (AFP, AP, Reuters)