Sao Paulo: The Brazilian city of Campinas, the second-largest in Sao Paulo state, on the night of Sunday and Monday registered at least 12 murders, some of which appear to be linked, authorities said.
Ten people were shot dead in two of the city`s neighbourhoods and at least two others died in hospitals where people wounded in the shootings were taken, police said.
The shootings happened within a span of four hours, according to media accounts.
At a press conference, the regional director of the Sao Paulo state police, Licurgo Nunes Costa, said that authorities are working with the hypothesis that the shootings are the result of a dispute among gangs of criminals, but they are not ruling out other lines of investigation.
"It`s evident that the murders have a connection. It was a sequence, one after the other, and in the western and southwestern regions of the city, in incidents very close to one another" and with victims between the ages of 17 and 30, Nunes Costa said.
In reprisal for the deaths, hooligans set three buses on fire in the neighbourhoods where the killings occurred.
Campinas is located 100 km from Sao Paulo city and is an industrial and university hub, with a metropolitan region containing 3.5 million people and consisting of 38 municipalities.
The city is to play host to the national soccer teams of Portugal and Nigeria during the 2014 World Cup in Brazil, which will be held in June and July.