WARSAW (REUTERS) - Poland summoned the Ukrainian ambassador on Wednesday to express concern over the use of force against demonstrators in Kiev, the Polish foreign ministry said.

"We condemn the use of force against peaceful demonstrations and express our earnest solidarity with the Ukrainian society that is peacefully protesting in the name of European values," the ministry said in a statement.

Earlier on Wednesday, Ukrainian riot police stormed Kiev's City Hall to try to force out anti-government protesters who have occupied the building, the protesters said.

The spokesman for the Polish foreign ministry, Mr Marcin Wojciechowski, said on Twitter that the Ukrainian ambassador to Poland was requested to come to the foreign ministry at 0900 GMT (5pm on Wednesday, Singapore time).