Intense exchanges of gunfire were heard when members of an elite police moved into the Pavao-Pavaozinho slum, which lies a few hundred yards (meters) from where Olympic swimming events are expected to take place in 2016. Residents blame police for the killing of the local man, whose body was found earlier in the day.
The O Globo newspaper, citing local health officials, reported that another resident of the slum was shot and killed, and a 12-year-old boy shot and wounded, during Tuesday night's gunfire. It's not clear who fired the shots that hit either, nor did police confirm the reports.
It was the latest violence to hit one of Rio's so-called "pacified" slums impoverished areas that for decades were controlled by drug gangs.
Police began an ambitious security program in 2008 to drive the gangs from such slums and for the first time set up permanent posts. It is part of Rio's overall security push ahead of the World Cup that begins this June and the Olympics the city will host.
So far, 37 such "police pacification units" have been created covering an area with a population of 1.5 million people.
But there have been repeated complaints of heavy-handed police tactics that have ended in the deaths of residents, and that is what set-off the latest clashes, resident said. More than two dozen police face charges from a high-profile case in a different shantytown, when investigators said a local man died while being tortured by police.
Slum residents have also lamented the lack of social services that had been promised to arrive along with the police presence in their communities.
Tuesday's violence erupted after the body of 25-year-old Douglas Rafael da Silva Pereira was found. He was a well-known figure in the community, as he was a dancer on a TV show for Brazil's Globo network, the nation's largest channel. The circumstances of his death aren't clear, but residents blame police.
"The police beat my friend to death, just like they've tortured and killed in other communities," said Johanas Mesquita, a 23-year-old resident of Pavao-Pavaozinho. "This effort to pacify the favelas is a failure, the police violence is only replacing what the drug gangs carried out before."
Police on the scene refused to answer questions about what prompted the violence. A spokeswoman reached by telephone said they didn't have an immediate statement.
Following the discovery of the body, angry young men began lighting fires throughout the slum and tossing homemade explosives, bottles and other objects down onto Copacabana's main avenues. Elite police units later entered the slum, and at least three prolonged exchanges of gunfire were heard, presumably between officers and the drug gang members who continue to maintain a presence in the shantytown.
In recent months, drug gangs have brazenly attacked police outposts, in what authorities themselves say is an effort to block the expansion of the "pacification" program and to win back lucrative drug-selling territory.
Since November, gunfights have regularly broken out in the slum where Tuesday's violence took place.