Troops took control of the perimeters of Vila Kennedy and two adjacent favelas, and helped police entering the impoverished neighborhoods, where drug gangs flourish.

An army sergeant and a police officer were reported murdered in the area earlier this week.

Police officers showed off pistols, ammunition, drugs and explosives they said had been confiscated during Friday's operation, AFP journalists said.

Despite sporadic outbreaks of gunfire, no one was hurt, a police spokesman said.

Similar operations take place regularly in Rio de Janeiro, where police have only loose control over large areas.

Citing a breakdown in law and order, President Michel Temer ordered the army to take over the command of security in the whole of Rio state a week ago.

It remains unclear how policies will change now that they are under control of generals, rather than civilian officials.