In a statement on Monday, President Luiz Inacio Lula da Silva joined the heads of the Supreme Court and the two houses of Congress to reject the acts of political violence that shook the capital, Brasilia, a day earlier.

The leaders called for calm “in defence of peace and democracy” and said they “reject the terrorist acts and criminal, coup-mongering vandalism that occurred” in the statement shared on social media.

Thousands of Bolsonaro supporters who refuse to accept the ex-army captain’s electoral defeat stormed Congress, the Supreme Court and the presidential palace on Sunday, with some calling for military intervention to restore Bolsonaro to power or remove Lula from office.

The incident came just days after Lula was sworn in as president on January 1, following one of the most divisive presidential elections in Brazil’s history. The left-wing leader narrowly defeated Bolsonaro in an October 30 runoff election, securing 50.8 percent of the total votes.

Bolsonaro, who never formally conceded defeat but authorised the presidential transition, had falsely claimed for months ahead of the election that Brazil’s electronic voting system was vulnerable to fraud – fuelling concerns he planned to contest the results.

Many of his supporters continue to believe the vote was stolen, and some erected roadblocks in the days after Bolsonaro’s loss. Others had also camped outside the military headquarters in Brasilia, demanding the army intervene.

On Monday, hundreds of soldiers and police mobilised to dismantle the improvised camp, where approximately 3,000 Bolsonaro supporters had set up tents. Around 1,500 people were arrested at the protest site, officials said.

Large contingents of riot police, meanwhile, deployed to lock down the capital’s Three Powers Square, home to the iconic modernist buildings that serve as the headquarters of the three branches of government.

Justice Minister Flavio Dino said the riot on Sunday amounted to “terrorism” and coup-mongering and that police have begun tracking those who paid for the buses that transported protesters to the capital.

“They will not succeed in destroying Brazilian democracy. We need to say that fully, with all firmness and conviction,” Dino said. “We will not accept the path of criminality to carry out political fights in Brazil. A criminal is treated like a criminal.”

In a news conference late on Sunday, Minister of Institutional Relations Alexandre Padilha also announced that the buildings would be inspected for evidence including fingerprints and surveillance images to hold people to account. He said that the rioters apparently intended to spark similar unrest nationwide.

The incident has drawn comparisons to the January 6, 2021 attack on the United States Capitol, which saw a mob of former US President Donald Trump’s supporters storm the legislature in an effort to stop Congress from certifying President Joe Biden’s election victory.

It has also spurred global condemnation, including from the leaders of Canada, the US and Mexico, who are meeting for trilateral talks in Mexico City this week.

“We stand with Brazil as it safeguards its democratic institutions,” Prime Minister Justin Trudeau and Presidents Biden and Andres Manuel Lopez Obrador said in a joint statement shared by the White House on Monday.

Carlos Pereira, a professor at Brazil’s Getulio Vargas Foundation, told Al Jazeera that the unified statement issued by Brazilian leaders was “a really bold and sound reaction” to what happened in the capital.

“It was sad to witness all [that] destruction,” Pereira said. “However, the stability of democracy should be observed not by the perspective of the aggressor, but [by] the capacity of the institutions to react.”

He added that it will be critical for Brazil to bring those responsible to justice, not only for the sake of accountability but also to deter others from taking similar actions. “It’s important to provide a response as soon as possible,” Pereira said.

Reporting from outside Congress on Monday afternoon, Al Jazeera’s Monica Yanakiew said calm had been restored to the area as the Brazilian authorities are assessing the damage.

“These protesters can be accused of trying to stage a coup, of destroying public property, of destroying objects of historical value, so it will not be easy for them. They won’t get off the hook that easily,” Yanakiew said.