Thousands rallied in the Albanian capital of Tirana on Monday as the opposition demanded Prime Minister Edi Rama’s resignation over corruption charges against his deputy, Belinda Balluku, whose parliamentary immunity has so far blocked her arrest.

The political crisis in the Balkan nation has been building for weeks since anti-corruption prosecutors accused Balluku of interfering in major state contracts. It reached its tipping point Monday night after Molotov cocktails were hurled at Rama’s office.

Four protesters were arrested during clashes and seven more put under investigation. Two police officers were injured, and one protester accidentally set himself on fire, local media reported.

The protest, organized by veteran opposition leader Sali Berisha and his Democratic Party, followed scenes of chaos in Albania’s parliament last week, when police intervened after lawmakers brawled and set off flares inside the chamber.

“We do not condone any form of violence — especially violence exercised by those in power. There is no more blatant form of violence than the extortion and systematic looting carried out by Edi Rama and his ministers against the Albanian people,” Berisha told POLITICO Tuesday via his spokesperson, saying the protests were intended to “stop this violence.”

Prosecutors and opposition lawmakers are pushing to lift Balluku’s immunity so that anti-corruption prosecutors can arrest and try her. Rama and his ruling Socialist Party have so far stalled the vote, saying they will wait for a Constitutional Court ruling that is expected in January.

Balluku is accused, along with several other officials and private companies, of manipulating public tenders to favor specific companies on major infrastructure projects, including Tirana’s Greater Ring Road and the Llogara Tunnel.

She has called the allegations against her “insinuations,” “half-truths” and “lies,” and agreed to cooperate with the judicial process fully. Balluku is also minister of infrastructure, overseeing some of the country’s largest public projects.

Rama has also defended Balluku amid the corruption charges, accusing the anti-corruption agency, known as SPAK, of normalizing pre-trial arrests, saying they amount to “arrests without trial” and fall short of European democratic standards.

The prime minister told POLITICO in an interview Wednesday that it was “normal” for SPAK to make errors as it is a “newborn institution with a newborn independent power” that has made “plenty of mistakes.”

When asked for a statement Tuesday about the protests’ violent turn, Rama refused to comment. He said he did not want to impugn his political opponents, “because in the end they are not enemies to be exposed to the world, but just desperate fellow Albanians, to be confronted and dealt with within the bounds of our own domestic political life.”

Berisha hit back, accusing Rama of stealing elections and telling him it was time to go.

“He has no legitimacy to remain in government for even one more day,” Berisha told POLITICO. Rama was reelected in May for a fourth term.