It will take 1,500 officers to secure a drug-infested slum near Rio's international airport ahead of major sports events to be hosted by Brazil, a police chief said Wednesday.
The planned operation is part of a drive launched in 2008 by state authorities to wrest control of shantytowns from drug gangs before the start of next year's World Cup and the 2016 Rio Summer Olympics.
"There is a plan that would involve deploying 1,500 military police officers" to occupy the Mare Complex, said Jose Luis Castro Menezes, the new chief of Rio state's military police.
"It is a challenge," he told Globo television.
The Mare Complex, a cluster of 15 favelas, is home to around 75,000 people.
No timeframe has been set for the operation.
In addition to the police, hundreds of military personnel usually take part in such operations and they sometimes turn violent.
In the midst of the football Confederations Cup in June, nine people were killed in a raid launched by the police's feared Special Operations battalion after one of its members was shot in the head and killed in one of Mare's slums.
Dozens of favelas once under the sway of narcotraffickers and para-police militias have been brought under police control, with the deployment of 33 so-called "pacification units."
Slum residents have generally welcomed the police presence.
But drug trafficking continues, albeit in a more discreet manner. And there have been allegations of police abuse, such as the case of Amarildo de Souza, a Rocinha shantytown resident who has been missing since he was picked up for questioning on July 14.