Thousands of protesters defied a curfew to gather overnight in Georgia's rebel Adzhara region and demand the resignation of its leader, who is locked in a stand-off with the central government.
Police loyal to rebel leader Aslan Abashidze blocked entrances to the city to prevent protesters gathering in the capital and key oil port of Batumi, according to media reports, which said 2,000 people had nevertheless demonstrated overnight.
"Two people have been injured, and have been taken to hospital ... hand grenades exploded and [police] have used automatic gunfire," said Givi Targarmadze, head of the Georgian parliament's security committee.
Abashidze has ignored demands by Georgian President Mikhail Saakashvili that he bring in reforms or step down, instead reinforcing his state of emergency, closing universities and sending police to disperse demonstrations.
Adzharan's forces turned fire-engine hoses on protesters on Tuesday and men in camouflaged uniforms attacked demonstrators with metal pipes.
Saakashvili called an emergency meeting of his security council in response and ordered the army in the region not to obey Abashidze.
Ex-Soviet Georgia, which faces separatist rebellions in two other regions, ordered Abashidze to bow to central rule by next Wednesday, after his local militia blew up bridges linking Adzhara with the Georgian heartland.
There was no evidence of compliance.
Georgian TV said he had taken all Tbilisi-based channels off the air.
The US, keen for stability in Georgia, which will be crossed by a major pipeline taking oil from the Caspian sea to a Turkish port, condemned the violent breakup of Tuesday's demonstration.
US-educated lawyer Saakashvili, 37, and former Soviet official Abashidze have been at odds since last November when Saakashvili led popular protests that dislodged former president Eduard Shevardnadze, a fellow politician from the Soviet era.
The resulting elections saw Saakashvili voted in as president.
Saakashvili calls the white-haired and diminutive Adzharan leader a relic of the past, while Abashidze calls the burly president a dangerous nationalist.
The Adzhara developments are fraught with dangers for relations between Georgia and its big northern neighbor, Russia, which retains Soviet-era military bases in the former Soviet republic.
Russia said on Tuesday, however, that the crisis was Georgia's internal affair.
RSS