Residents of a Brazilian slum found at least eight bodies Monday in a mangrove swamp on the outskirts of Rio de Janeiro after an "intense" shootout during a police operation, authorities said.
Rio de Janeiro state police said officers were investigating the grisly scene alongside forensics experts in the poor favela neighborhood of Salgueiro, around 35 kilometers (20 miles) northeast of the iconic beach city.
The network showed rolling images of unidentified cadavers draped in white sheets at the edge of the swamp, part of the municipality of Sao Goncalo.
State police said clashes first erupted in the area Saturday, when a police sergeant on patrol was killed in an attack.
Rio's Police Special Operations Battalion, or BOPE, then raided the area Sunday.
Rights groups regularly accuse the elite force of indiscriminate killing and excessive violence in its hard-hitting operations against drug gangs in the favelas.
"The BOPE executed an operation in Salgueiro Sunday after receiving information that one of the individuals involved in Saturday's attack was believed to be wounded and hiding in the area," police said.
Police said they seized two pistols, ammunition, more than 800 bricks of marijuana and more than 3,000 packets of a substance resembling crack cocaine in the raid.
It was the 58th shooting incident with three or more victims so far this year in Rio state, said rights group Fogo Cruzado, which monitors violence in the state.
Of those, 43 were during police operations, it said.
In May, a bloody raid targeting alleged drug traffickers in the favela of Jacarezinho left 28 people dead, some reportedly killed in cold blood.
The incident, which drew international condemnation, was the deadliest police operation in Rio history.