Police said Sunday that they killed two other suspected drug traffickers in overnight clashes near the Morro dos Macacos ("Monkey Hill") slum where the gangs fought for territory a day earlier. But the area was largely peaceful.
Two officers died and four were injured Saturday when bullets from the gang battle ripped into their helicopter hovering overhead, forcing it into a fiery crash landing on a soccer field. Officials said they did not know if the gangs targeted the helicopter or it was hit by stray bullets.
Gunfire on the ground killed 10 suspected gunmen and wounded two bystanders.
Authorities said the violence only toughened their resolve to improve security ahead of the Olympics and before 2014, when Brazil will host the World Cup soccer tournament with key games in Rio, the country's second-biggest city.
Rio state Public Safety Director Jose Beltrame told reporters that the violence was limited to a specific area of the city of 6 million and "is not a problem throughout all of Rio de Janeiro."
He said authorities will follow through with promised efforts to reduce crime.
"We proved to the Olympic Committee that we have plans and proposals for Rio de Janeiro," Beltrame said. "We proved that our current policy not only consists of going into battle, it also consists of keeping the peace."
Rio state Gov. Sergio Cabral said earlier that the city's security challenges can't be cured "by magic in the short term." But money is being poured into programs to reduce crime and authorities are prepared to mount an overwhelming security presence at the sporting events to ensure safety, he said.
Saturday's fighting raged about five miles (eight kilometers) southwest of one of the zones where Rio's 2016 Olympics will be held.
It was on Oct. 2 that the city was chosen over Chicago, Madrid and Tokyo to host the games. Rio alone among the bid cities was highlighted for questions about security ahead of the vote by the International Olympic Committee.
Rio is one of the world's most dangerous cities. Although violence is mostly contained within its sprawling shantytowns, it sometimes spills into posh beach neighborhoods and periodically shuts down a highway linking the international airport to tourist destinations.
Brazilian President Luiz Inacio Lula da Silva has played down the threat of violence for the Olympics, saying Rio has repeatedly demonstrated it can put on big events without risks to participants. The Pan-American Games in 2007 were held without major incidents after authorities deployed 15,000 specially trained officers.
More lasting change is needed now to protect Rio's citizens, said 83-year-old Maria Jose Gonzaga, who awoke to gunfire Saturday near the violence zone and cowered at home for hours until it finally ended.
"As soon as Saturday began, they started shooting at each other," Gonzaga said. "It was very intense, very awful indeed."
Associated Press Writers Marco Sibaja in Brasilia, Brazil, and Alan Clendenning and Bradley Brooks in Sao Paulo contributed to this report.