RIO DE JANEIRO (Reuters) - At least 13 people were killed in clashes with police just outside Brazil's seaside city of Rio de Janeiro after a raid to arrest a gang leader, police said on Thursday, marking another bloody episode in the sprawling metro area.

The clashes took place in the working-class Salgueiro neighborhood in the city of Sao Goncalo, northeast of Rio de Janeiro, Brazil's second-largest city.

According to the police, those killed were all suspected criminals.

Leonardo Costa Araujo, accused of being a drug gang leader from the northern state of Para, is among the dead. He was implicated in the death of several police officers in Para in recent years and police believed he was hiding in the area.

The raid on Thursday sought to arrest Araujo in an operation that also employed helicopters and armored vehicles, according to police.

Rio state police forces regularly carry out deadly raids in the metro area's sprawling slums.

"We will not allow Rio to be used as a hideout for bandits from other states," Governor Claudio Castro of Rio de Janiero state wrote in a post on social media.

Three local residents with no suspected criminal connections were also shot and injured during the clashes, the police added.

(Reporting by Rodrigo Viga Gaier; Writing by Carolina Pulice; Editing by David Alire Garcia and Gerry Doyle)