RIO DE JANEIRO - At least 11 people were shot and killed in a bar in Brazil's northern state of Para on Sunday, police said.

The shooting took place Sunday afternoon in the neighborhood of Guama in the city of Belem when seven gunmen arrived at the bar and began shooting. They killed six women, among them the bar's owner, and five men, according to the Military Police.

One person was injured and taken to hospital under police protection.

An investigation into the shooting was opened by the Civil Police's Homicide Division, but the motive behind the shooting is still unknown.

Local media speculated that the killings could be a revenge for a fight among rival factions.

The Guama neighborhood is one of the most populous neighborhoods in Belem and in March it was one of seven to receive reinforcement from the National Armed Forces to put a stop to criminal activity in the city and the metropolitan region.

In 2017, a wave of killings hit Belem, killing 28 people in 24 hours following the murder of a military police officer.