RIO DE JANEIRO (AP) — Supporters of Brazilian President Jair Bolsonaro clashed with police Monday, setting fire to several vehicles and allegedly attempting to invade the federal police’s headquarters in capital city Brasilia.

Images of chaos as a small number of protesters, many wearing the yellow and green of Brazil's flag that has come to symbolize Bolsonarismo, roamed the city, circulated on local television channels and social media.

Brasilia's public security secretariat said in a statement that clashes broke out after police carried out an arrest warrant. Earlier that day, Supreme Court justice Alexandre de Moraes had ordered the temporary arrest of José Acácio Serere Xavante, suspected of participating in anti-democratic protests.

Since Bolsonaro lost re-election to da Silva on Oct. 30, many of his supporters have gathered outside military barracks across the country refusing to concede defeat and asking for the armed forces to intervene. Earlier Monday, the nation's electoral authority awarded da Silva and his vice president an official certification, sealing their victory.

Bolsonaro, who has repeatedly claimed that the nation's electronic voting system is prone to fraud and has not conceded defeat, told supporters Friday that his political future was in their hands.

“The depredation and attempted invasion of the Federal Police building in Brasilia is unacceptable,” said Flavio Dino, future Justice and Public Security Minister in the upcoming administration of President-elect Luiz Inácio Lula da Silva.

The leader of the opposition in the Senate, Randolfe Rodrigues, said some protestors, whom he called “terrorists,” had concentrated around the hotel where da Silva is staying.

Police in full gear were rushed to the Federal Police’s headquarters as back up, as officers had to use stun grenades and rubber bullets, local media reported. Police also blocked several avenues and streets across Brasilia

Protesters elsewhere set at least one bus on fire and were seen gathering metal barriers.