Georgia's ruling party has swept to victory in nationwide municipal elections. It was the first electoral test for pro-West President Mikheil Saakashvili since the country's 2008 war with Russia.

Exit polls show the United National Movement party won at least 60 percent of the vote in a series of municipal council elections.

But opposition leaders have refused to concede defeat, saying the elections were marred by problems with voter lists and illegal campaigning by the ruling party.

Europe's top election watchdog will deliver its report on the vote later on Monday.