SAO PAULO Ė Six people were killed and another wounded within the space of 30 minutes in three separate drive-by shootings across a single neighborhood in Brazilís largest city, police said on Thursday.
Police said Wednesday nightís incidents might be related to each other.
Authorities are also investigating a possible connection to the earlier fatal shooting of a police officer in the same neighborhood.
The violence in Parelheiros, on Sao Pauloís south side, began just after 9:30 p.m. and according to witnesses, in each case the shots were fired from a speeding car.
In the first incident, three men ranging in age from 21 to 26 where shot as they stood on the street talking. One was pronounced dead at the scene, another died later at a hospital and the third remains in grave condition.
Two other people were then fatally shot a few blocks away before a man and his son were killed by bullets fired from a moving car as they were leaving a Parelheiros restaurant.
Shell-casings found at the crime scenes indicate that at least four different guns were used, police said.
Sao Paulo, once one of Brazilís most violent cities as measured by the number of murders, managed in recent years to bring killings below the level designated by the World Health Organization as endemic: more than 10 homicides per 100,000 residents.
Latin Americaís most-populous metropolis recorded 1,130 homicides in 2014, compared with 1,161 in 2013.