Mucio spoke to reporters following a meeting between President Luiz Inacio Lula da Silva and the chiefs of the army, navy and air force -- the first such meeting since the January 8 riots.

"I understand that there was no direct armed forces involvement, but if any element participated, they will have to answer as citizens," said Mucio.

Just days after the attack on the presidential palace, Supreme Court and Congress by backers of far-right ex-president Bolsonaro, Lula said the rioters likely had inside help and hinted at security force involvement.

He has since sacked more than 50 soldiers from his security detail.

Commanders Julio Cesar de Arruda, of the army, Marcos Olsen, of the navy, and Marcelo Damasceno, of the air force, accepted that members of the armed forces found to have been involved in the riots would be punished, said Mucio.

More than 4,000 Bolsonaro supporters caused havoc in Brasilia, smashing furniture, defacing facades and even damaging priceless works of art.

They also left behind graffiti calling on the military to stage a coup.

More than 2,000 people have since been arrested and close to 1,400 of them remain in detention.

They are accused of "anti-democratic actions" and the public prosecutor has so far initiated formal proceedings against 39 people.