Buses and cars were set on fire as crowds, many of whom were wearing their trademark yellow national football jerseys or were draped in Brazilian flags, confronted security forces.

It began after a Bolsonaro supporter was detained for allegedly organising violent "anti-democratic acts," according to the judge who ordered his arrest.

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

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

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 Mr Lula from office.

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

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

"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."

The conspiracy theories and subsequent violence have rekindled memories of the January 2021 invasion of the US
Capitol by supporters of former President Donald Trump.

It also raises security concerns about 1 January, when Mr Lula will take office in a public ceremony in Brasilia.

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

Mr Lula's team denied reports that he would be removed from the hotel by helicopter.