Thousands of anti-government protesters rallied in Georgia on Tuesday after the arrest of an opposition leader, deepening a political crisis that erupted after disputed elections last year.

Hundreds of riot police used tear gas against Nika Melia's supporters, who were camped out at his United National Movement party's headquarters in the capital Tbilisi before he was arrested in an overnight police raid and placed in pre-trial detention.

Garibashvili was confirmed as prime minister by parliament on Monday
Garibashvili was confirmed as prime minister by parliament on Monday AFP / Vano SHLAMOV

The move sparked swift condemnation from the opposition and Western diplomats, as fears mount over the ex-Soviet nation's fragile democracy.

In the afternoon, several thousand anti-government protesters rallied outside the parliament building in central Tbilisi to denounce Melia's arrest and demand early elections. They also blocked traffic along the city's main thoroughfare.

Demonstrators are calling for the release of detained Georgian politician Nika Melia and early elections
Demonstrators are calling for the release of detained Georgian politician Nika Melia and early elections AFP / Vano SHLAMOV

"We urgently need free and fair elections to get rid of a government that is destroying democracy," Ilia Togonidze, a 20-year-old student, told AFP at the rally.

Scores of Melia's supporters were also detained in the morning raid and the leader of the opposition Lelo party called for "a peaceful, unwavering struggle to defend Georgian democracy".

Opposition politicians have called for more protests as Georgia's political crisis deepens
Opposition politicians have called for more protests as Georgia's political crisis deepens AFP / Vano SHLAMOV

"Liberation of political prisoners and snap parliamentary elections are the only possible way out of the crisis," Mamuka Khazaradze said, speaking to journalists on behalf of all opposition leaders.

At the afternoon rally, opposition leaders called for a mass protest march in Tbilisi on Friday.

IMAGESGeorgian police arrest a top opposition leader and use tear gas in a violent raid on his party headquarters, further deepening a political crisis sparked by last year's disputed parliamentary elections. Local television footage shows Nika Melia, the
IMAGESGeorgian police arrest a top opposition leader and use tear gas in a violent raid on his party headquarters, further deepening a political crisis sparked by last year's disputed parliamentary elections. Local television footage shows Nika Melia, the leader of the United National Movement, the country's main opposition party, being dragged from his party headquarters to be placed in pre-trial detention. Formula TV
A court ordered Melia placed in pre-trial detention after he refused to pay an increased bail fee
A court ordered Melia placed in pre-trial detention after he refused to pay an increased bail fee AFP / Vano Shlamov

The United States led the chorus of international condemnation of Melia's arrest.

State Department spokesman Ned Price said the United was "deeply troubled" and warned that the move went against Georgia's aspirations for closer integration with the West.

Georgian police detain an opposition supporter during the rally
Georgian police detain an opposition supporter during the rally AFP / Vano Shlamov

"Polarizing rhetoric, force and aggression are not the solution to Georgia's political differences," Price said.

"We call on all sides to avoid actions that could further escalate tensions and to engage in good-faith negotiations to resolve the current political crisis."

Irakli Kobakhidze, chairman of the ruling Georgian Dream party, defended the police raid.

Opposition politicians have called for more protests as Georgia's political crisis deepens
Opposition politicians have called for more protests as Georgia's political crisis deepens AFP / Vano SHLAMOV

"Polarisation is a result of criminals being in politics, not of so-called politicians being in jail," he said in a televised statement.

Georgia has been in the grip of a political crisis since parliamentary elections in October, which opposition parties slammed as rigged after Georgian Dream claimed a narrow victory.

Opposition members have refused to take up their seats in the new parliament, in a boycott that has weighed heavily on the ruling party's political legitimacy.

On Thursday, Prime Minister Giorgi Gakharia resigned over Georgian Dream's plans to arrest Melia.

A court in Tbilisi last week had ordered Melia to be placed in pre-trial detention after he refused to pay an increased bail fee ahead of hearings in a case related to anti-government demonstrations in 2019.

He has been charged with "organising mass violence" during the protests and faces up to nine years in prison.

Melia, 41, rejects the case as politically motivated.

Georgia's new Prime Minister Irakli Garibashvili, who was confirmed by parliament on Monday, had said in an address to lawmakers Melia "will not manage to hide from justice".

Garibashvili is a loyal lieutenant of the powerful oligarch Bidzina Ivanishvili, who founded Georgian Dream and is widely seen as the man in charge in Georgia, despite having no official political role.

In power since 2012, Georgian Dream has seen its popularity fall over a failure to address economic stagnation and perceived backsliding on commitments to democracy.

The move to arrest Melia may further stoke anger against the party.

At Tuesday's protest, 49-year-old painter Manana Tkeshelashvili told AFP that "Georgian Dream had dug its own political grave today by arresting Melia".