Twenty-two killed in Brazilian beach city

"The murders took place between Saturday and Sunday and could have been connected to a power struggle after the arrest of gang leaders," Kalina Leite, secretary for security in the state of Rio Grande, told AFP in a statement.

On Thursday, 13 people were arrested in a major police swoop against a narcotics and money laundering gang in the Mosquito slum in the north of Natal, police said.

An investigation was underway into the latest violence.

Brazil, which hosts next year's Olympics in Rio de Janeiro, has one of the highest murder rates in the world.