Masked gunmen killed 11 people indiscriminately after bursting into a bar in the northern Brazilian city of Belém on Sunday, ONA reports citing BBC.
The shooting happened in Guamá, a poor and violent neighborhood of the city in the Amazon region.
Local media speculated that the shooting was carried out by a gang in retaliation for the deployment in March of federal forces to Belém.
So far, no arrests have been made in connection with the crime.
Military police said seven armed men had arrived at Vanda's bar in a car and on three motorbikes on Sunday afternoon, local time.
Witnesses said the masked assailants appeared to shoot at random, killing five women and six men. One person was injured and is under police protection.
While the owner of the bar was reportedly among those killed, many people were able to flee through a back door.