President Mikhail Saakashvili declared a state of emergency in the Georgian capital Tbilisi this evening after police fought pitched battles with protesters, and the prime minister said there had been an attempt at a coup.
"The president has declared a state of emergency in Tbilisi and this decision will be submitted to
Police walk by as they guard the television station Imedi in Tbilisi.
parliament within 48 hours," Prime Minister Zurab Nogaideli said on television.
"There was an attempt at a coup and creating disorder."
Riot police armed with batons repeatedly clubbed and kicked unarmed demonstrators in Tbilisi, firing tear gas and rubber bullets to clear the streets, reporters at the scene said.
Special forces stormed an opposition TV station and Mr Saakashvili blamed Russia for the crisis in the former Soviet state, now an US ally.
Mr Saakashvili announced he was expelling three Russian diplomats from Georgia and withdrawing his ambassador from Moscow, claiming he had evidence that Russian intelligence was behind six days of mass protests.
"We cannot let our country become the stage for dirty geo-political escapades by other countries," he said in a television broadcast. "Our democracy needs a firm hand of the authorities."
Shortly after his remarks, the main opposition television station Imedi said it had been stormed by Georgian special forces and went off the air. Imedi had been broadcasting extensive coverage of the opposition demonstrations.
Witnesses at the scene said armed police had forced staff to the floor, smashed equipment, destroyed mobile phones and put guns to employees' heads.
Mr Saakashvili has previously trumpeted his country as a shining example of democracy and respect for human rights in the volatile Caucasus region, which is mainly governed by authoritarian leaders.
In a sign of international concern, the European Union said it was sending its special envoy for the South Caucasus, Peter Semneby, to Georgia to meet "all the relevant parties".