Tbilisi: A Georgian opposition party called for a "Day of Rage" on Wednesday to try to force President Mikheil Saakashvili to resign after police used teargas and rubber bullets against protesters in the capital.
The protesters, who numbered around 10,000 on Saturday, accuse Saakashvili of imposing autocratic rule on the former Soviet republic that sits on energy transit routes from the Caspian to western Europe.
Echoing language used to rally protesters in the uprisings in the Arab world, Sozar Subari, chairman of the opposition Georgian Party, said: "We are calling our supporters to come to the rally on May 25 and we call this day `Day of Rage`."
He told a news conference on Sunday the state was using its power against its own people.
An Interior Ministry spokesman said the police had intervened when a group of 10 protesters started smashing the windows of a police car with metal poles. Protesters had camped out in Tbilisi overnight.
"Police used teargas and rubber bullets against that aggressive group of protesters ... There was no intention to disperse the rally," spokesman Shota Utiashvili said.
Protesters said a group of them attacked the police car because they wanted to release an activist who had been detained. Independent Maestro television reported that one woman was taken to hospital.
By early evening, 2,000 people gathered near TV building in Tbilisi to hear about what further action was planned.
"Our doors are open to other opposition political parties. We expect that more people will join our protest and this regime will be over very soon," Nino Burjanadze, former Saakashvili ally and Parliament speaker, told the crowd.
Former defence minister Irakly Okruashvili -- who is wanted by Georgian authorities and is in exile in Paris -- promised to return to Georgia on May 25 to join his Georgian Party colleagues.
"I can promise you two things -- that I will be in Georgia on May 25 and that this day will be the last one for this government," Okruashvili told Maestro television.
The rally would be on the day before Georgia marks its 20th anniversary of independence on Thursday.
Opponents of the pro-Western Saakashvili accuse him of monopolising power since the 2003 "Rose Revolution" that ousted the post-Soviet old guard in the Caucasus state.
Weakened by the brief war with Russia in 2008, Saakashvili has since reasserted control, aided by an ineffective and patchy opposition.