Around 300 protesters maintained an overnight vigil outside the Georgian public television studios in the capital Tbilisi, many armed with sticks after brief clashes on Sunday when police used rubber bullets and tear gas against demonstrators who attacked cars.

They said they wanted to defend the protest venue against any possible crackdown.

"We will stay here until they throw us out," protester Lasha Oniani told AFP.

The opposition accuses Saakashvili of becoming increasingly authoritarian, failing to tackle widespread poverty and losing large parts of Georgian territory during the country's disastrous war with Russia in 2008.

Opposition leader Nino Burjanadze has said that a "revolution" has started in Georgia, but turnout at the protests has been relatively small, with around 6,000 attending rallies on Saturday and fewer on Sunday.

The authorities say protests will be allowed to continue unhindered as long as they remain peaceful.