Brazilian police said they killed at least 10 suspected drug traffickers on Monday after gunmen cornered a group of officers in a Rio de Janeiro slum.
Police who had entered the slum in Brazil's second-biggest city to retrieve a stolen truck called in reinforcements including two helicopters after they were surrounded by armed gang members, a police spokeswoman said.
"It was an operation to retrieve stolen goods and the police came under fire," Rio Civil Police official Renata Nunes said.
Daily clashes between police and heavily armed drug gangs that control hundreds of slums make Rio one of the world's most dangerous major cities.
Police routinely say that those killed in their raids are suspected drug traffickers, but human rights groups have accused them of brutality and summary executions. Innocent residents are often caught up in the violence.
Police used pepper gas on Monday night to disperse a crowd of relatives and friends of the dead and wounded suspects who had gathered outside the hospital where they were taken, hospital officials said.
Under a tougher policy of "confrontation" with the drug gangs, Rio police reported they killed 1,330 suspects last year, up about 25 percent from the previous year.
The police said at least one officer was wounded in Monday's gun battle in the impoverished Baixada Fluminense area of the city.