The comment by General Eduardo Villas Boas was his second high-profile remark on the state of Brazil's democracy this month, going against an unwritten rule that high-ranking military officers keep out of politics.

"We can't be indifferent to the more than 60,000 murders a year, the banalization of corruption, the impunity, the insecurity caused by organized crime and the ideological politicization of national problems," the general said in a speech marking army day.

"These are real threats to our democracy."

Villas Boas caused a stir on April 3 when his criticism of "impunity" for corrupt politicians was seen as a direct appeal for the Supreme Court to authorize prison for ex-president Luiz Inacio Lula da Silva, who was jailed for corruption that same week.

His comments come with the army playing a more high-profile role after President Michel Temer ordered the military to take over security in Rio de Janeiro, where police struggle to cope with violent crime.

The general spoke Thursday alongside Temer, who himself has been charged twice with corruption but so far remains protected by Congress from having to face a trial.

Brazil's military is highly respected but has kept largely clear of politics since the return of democracy in 1985 after two decades of dictatorship.