Brazilian authorities say there has been a "massacre" in the country's northern Pará state without releasing any details, while Brazilian news media say gunmen attacked a bar in Belem City and killed 11 people.

The G1 news website says police reported that seven gunmen opened fire on a bar. G1 says police also report one wounded in the attack.

A Pará state spokeswoman, Natalia Mello, says she can only "confirm" there was a massacre in the state.