Supporters of far-right Brazilian President Jair Bolsonaro on Monday attempted to invade the federal police headquarters in the capital Brasilia, in a flash of post-election violence on the day the president's electoral defeat was certified

A woman walks near a bus on fire as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Reuters witnesses saw Bolsonaro supporters, many in their trademark yellow national soccer jerseys or draped in Brazilian flags, confronting security forces at police headquarters.

Supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Police fired stun grenades and tear gas to disperse the crowd. Nearby buses and cars were set on fire.

A vehicle is seen on fire as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Federal police said "disturbances" near the headquarters were being handled with support from capital security forces. The violence unfolded after a Bolsonaro supporter was detained for allegedly organizing violent "anti-democratic acts," according to the judge who ordered his arrest.

People gesture as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Earlier on Monday, the federal electoral court (TSE) certified the Oct. 30 election victory of Bolsonaro's leftist rival, Luiz Inacio Lula da Silva, as president.

A firefighter works to put out a fire as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

After months of baseless suggestions that Brazil's voting system is vulnerable to fraud, Bolsonaro has neither conceded defeat to Lula nor has he formally blocked the handover of power.

Supporters of Brazil's President Jair Bolsonaro face off with police in Brasilia, Brazil, Dec. 12, 2022.

But some of the president's most diehard supporters have blocked highways in protest and camped out in front of army barracks, calling for a military coup to bar Lula from office.

A police officer fires a shotgun as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Hundreds of Bolsonaro supporters gathered outside the presidential residence on Monday afternoon with banners calling for "military intervention."

Police officers stand guard as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

The president joined them for a public prayer but did not address the crowd.

Police officers stand guard as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

"There's not going to be an inauguration," said Jose Trindade, 58, one of the Bolsonaro supporters in the crowd. "Bolsonaro was re-elected, but they stole it. So only the army can put things in order."

Police officers stand guard as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Senator Randolfe Rodrigues, a key Lula aide, said there were concerns about the physical safety of Lula and Vice President-elect Geraldo Alckmin, as protesters had surrounded the hotel where he is staying in Brasilia.

Police officers pass near a bus on fire as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Sparked by arrest

The violence in Brasilia came after Supreme Court Justice Alexandre de Moraes, who has led probes into Bolsonaro and his allies, on Monday ordered the temporary arrest of Jose Acacio Serere Xavante for allegedly carrying out anti-democratic acts.

A man is seen near a car on fire as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Xavante, an Indigenous leader, is among the Bolsonaro supporters who have protested in defiance of the Oct. 30 election result.

Firefighters work to put out a fire as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

"I cannot accept criminals reigning in Brasil," Xavante tweeted last month. "Lula cannot be certified."

A police officer throws a canister as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

Last week, Bolsonaro broke weeks of post-election silence to say that his situation "hurts my soul."

A bus is seen on fire as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

"Who decides where I go are you. Who decides which way the armed forces go are you," Bolsonaro told his supporters at the gates of the presidential residence on Friday.

A woman gestures in front of police officers on horses as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

In a statement, the Supreme Court said Moraes "decreed the temporary arrest, for 10 days, of the indigenous José Acácio Serere Xavante, due to evidence of the commission of crimes of threat, persecution and violent abolition of the Democratic State of Law."

Security forces take position as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.

It said Xavante had led protests across Brasilia and had used "his position as chief of the Xavante people to enlist indigenous and non-indigenous people to commit crimes," threatening Lula and Supreme Court justices.

A police officer fires a shotgun as supporters of Brazil's President Jair Bolsonaro protest in Brasilia, Brazil, Dec. 12, 2022.