Police revenge theory in Sao Paulo killing spree
At least 19 people have been shot dead within the space of about three hours in Brazil's biggest metropolitan area, police said.
Alexandre de Moraes, head of Sao Paulo State Public Safety Department, said at a news conference that detectives are trying to determine if the shootings in the suburbs of Osasco, Barueri and Itapevi, on the western outskirts of Sao Paulo, are related.
He said 15 of the victims were shot dead in Osasco, three in Barueri and one in Itapevi. Seven people were wounded and are being treated in hospital.
The mayor of Osasco, Jorge Lapas, told the Globo TV network the killings might have been in reprisal for the recent shooting deaths of two police officers.
At least 10 of the dead were shot at a bar after hooded men got out of a car and opened fire.
Not far away, one young man was shot outside an ice cream store, and another was shot by two men riding a motorcycle.
Other shootings took place in at least five other areas.
Citing witnesses, Mr Moraes said that in at least two instances, gunmen wearing face masks arrived and asked who had criminal histories. Those who said they had were shot.
"We will investigate if the killings were committed by drug traffickers, by off-duty police officers or were acts of vengeance for the recent killings of two police officers."