Brazilian President Luiz Inacio Lula da Silva has condemned "acts of terrorism" while security forces arrested over 1,500 people from protest camps after a far-right mob wreaked havoc on the country's seat of power earlier Sunday.

Hundreds of soldiers and police mobilized to dismantle and clear the improvised camp outside the army's headquarters in Brasilia.

There, some 3,000 supporters of ex-president Jair Bolsonaro had set up tents – used as a base for the sea of protesters who ran riot inside the presidential palace, Congress and Supreme Court for around four hours Sunday.

Lula, who took office on Jan. 1 after a bitterly divisive election win over Bolsonaro, returned to work in the pillaged presidential palace, where AFP reporters saw the wreckage that remained of the previous day's havoc: trashed artwork and offices, shattered windows and doors, broken glass strewn across the floor, and furniture dragged into a reflecting pool.

Lula, the 77-year-old veteran leftist who previously led Brazil from 2003 to 2010, met with the leaders of both houses of Congress and the chief justice of the Supreme Court and joined them in condemning what many called the South American country's version of the U.S. Capitol riots in Washington two years ago.

"The three powers of the republic, the defenders of democracy and the constitution, reject the terrorist acts and criminal, coup-mongering vandalism that occurred," they said in a joint statement.

Lula accepted an invitation to meet with President Joe Biden next month in Washington, U.S. officials said.

Bolsonaro hospitalized

Bolsonaro, who narrowly lost the October elections, meanwhile said on Twitter that he had been hospitalized in Florida with abdominal pains stemming from a near-fatal knife attack when he was campaigning for the presidency in 2018.

Bolsonaro has alleged he is the victim of a conspiracy against him by Brazil's courts and electoral authorities.

The ex-president, dubbed the "Tropical Trump," traveled to Orlando on the second-to-last day of his term – snubbing Lula's inauguration, in a break with tradition.

Bolsonaro, 67, took to Twitter Sunday night to condemn the "pillaging" in Brasilia, but rejected Lula's claim he incited the attacks and defended the right to "peaceful protests."

'Traces of Trumpism'

As the nation continued to come to grips with Sunday's stunning violence, hundreds of people gathered along a major avenue in downtown Sao Paulo to defend Brazilian democracy and demand punishment for the people who stormed the halls of power a day earlier.

"I have not endured what I have in this life to see what I saw yesterday – my people, my country, divided in such a way," said Edi Valladares, a 61-year-old teacher.

The demonstrators included young people, entire families, labor union activists, anti-racism advocates and others, with banners reading "We are with Lula and for democracy" and "Respect for the people's vote."

Earlier in the day, large contingents of riot police 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.

Condemnation continued to pour in from around the world, with Pope Francis criticizing the unrest as a sign of the "weakening of democracy" in the Americas.

In a joint statement ahead of summit talks in Mexico City, Biden, Mexican President Andres Manuel Lopez Obrador and Canadian Prime Minister Justin Trudeau condemned the attacks and said they "stand with Brazil as it safeguards its democratic institutions."

In a show of firm support, Biden spoke with Lula by phone Monday and invited him to visit the White House in early February. The Brazilian leader accepted, the White House said.

Biden told Lula of his support for "the free will of the Brazilian people as expressed in Brazil's recent presidential election, which President Lula won," the White House said in a statement.

Many drew the inevitable comparison to Jan. 6, 2021, when supporters of then-U.S. president Donald Trump invaded the Capitol in Washington in a violent, failed bid to stop Congress from certifying his election loss.

Investigation begins

Lula, who was in the southeastern city of Araraquara visiting a flood-hit region when the riot started, signed a decree Sunday declaring a federal intervention in Brasilia, giving his government special powers over the local police force to restore law and order in the capital.

His government vowed to find and arrest those who planned and financed the attacks.

Supreme Court Justice Alexandre de Moraes suspended Brasilia Governor Ibaneis Rocha, a Bolsonaro ally, from his post for 90 days, on grounds of "criminal negligence."

Moraes also ordered the security forces to disperse anti-government protests outside military bases nationwide.

Hardline Bolsonaro supporters have been protesting outside army barracks calling for a military intervention to keep Lula from power since his election win.

Following the ruling, soldiers and police broke up camps in Rio de Janeiro and Sao Paulo, as well as Brasilia.

Lula narrowly won the October 30 runoff election by a score of 50.9% to 49.1%.