The clashes on Sunday morning, which left several people injured, followed a protest rally a day earlier that attracted thousands to the centre of Tbilisi.
A small contingent of protesters remained through the night outside the headquarters of the state broadcasting company in the capital.
Around two dozen opposition supporters also attacked a police car after officers reportedly tried to arrest one of the protest leaders.
Riot police then fired tear gas and rubber bullets to disperse the crowd.
Demonstrators accuse Georgian President Mikhail Saakashvili of corruption and of blocking democratic reforms.
