There have been mass anti-government protests since mid-April, when the ruling Georgian Dream party reintroduced plans to pass a law critics say resembles Russian legislation used to silence dissent,
France 24 reports.
Waves of similar street protests -- during which police used tear gas and water cannon against demonstrators -- forced the party to drop a similar measure in 2023.
Police have again clashed with protesters during the latest rallies.
On Sunday evening -- before staging what organisers called a "March for Europe" -- at least 20,000 people turned out at Tbilisi's central Republic Square, according to an AFP estimate.
The kilometre-long procession, which featured a huge EU flag at its head, stretched out along Tbilisi's main thoroughfare towards parliament.
"I am here to protect Georgia's European future," said 19-year-old Lasha Chkheidze. "No to Russia, no to the Russian law, yes to Europe."
The rally was organised by around 100 Georgian rights groups and opposition parties, which have until now kept a low profile at the youth-dominated daily protests.
"The authorities, which have reintroduced the Russian bill, are going beyond the constitutional framework and changing the country's orientation, betraying the unwavering will of the people," the organisers said in a statement.
At one point during the largely peaceful rally, demonstrators attempted to break through a police cordon outside the parliament building to hoist an EU flag there, an AFP journalist witnessed.
Police used pepper spray without warning.
The interior ministry said in a statement that "the protest turned violent" and that "demonstrators physically and verbally confronted law enforcement."
Past midnight, hundreds of riot police were deployed in the area.
