A Reuters reporter saw three protesters being arrested, including Nika Melia, a leader of the country's largest opposition party, the Coalition for Change.
Interfax news agency reported that Melia has since been released on bail after detention for an administrative offence.
Georgian opposition leader Nika Melia claims he was kicked by police after being arrested. (EPA PHOTO)
"At the police station, I was sitting on a chair in handcuffs and was kicked by a police officer," Interfax cited Melia as telling journalists afterwards.
Reuters could not independently verify the information.
There was no immediate comment from the police. Georgia's Ministry Of Internal Affairs had said in a statement before the protest that the police would ensure the rally took place "in a peaceful environment, within the limits established by law."
Former Tbilisi Mayor Giorgi Ugulava was also arrested, local media reported.
Georgians have been rallying nightly since November, when the ruling Georgian Dream party said it was suspending European Union accession talks until 2028, abruptly halting a long-standing national goal.
Georgian Dream held onto power in a disputed election in October that opposition parties say was rigged. The government says the vote was fair and free.
Protests had dwindled in recent weeks but they resumed with greater force on Sunday when thousands of people gathered outside a shopping complex on the northern edge of Tbilisi and briefly blocked the road leading out of the city. Police presence at the rally was considerable.
Earlier on Sunday, the Interior Ministry warned protesters in a statement that blocking the motorway was a criminal offence.
One protester was seen by the side of the road, unconscious. Reuters was unable to establish what had happened to him.
Unverified video footage posted on social media showed scores of police in balaclavas beating protesters on the streets and others carrying away injured demonstrators into ambulances.
