An elite police unit killed nine people during an operation targeting drug traffickers in Varzea Paulista, a city about 50 kilometers (31 miles) from Sao Paulo, Brazilian officials said.
Six of the nine suspects killed in Tuesday's operation have been identified and all had lengthy criminal records, the Sao Paulo Security Secretariat said.
Forty officers from two squads of the ROTA special operations battalion took part in the operation, which also resulted in the arrests of eight other suspects.
Officers seized a large quantity of firearms and some marijuana in the operation, the secretariat said.
Police received an anonymous tip that the gang was going to conduct a summary trial of a man accused of committing a rape on a rural property outside Varzea Paulista.
Officers went to the ranch on Tuesday afternoon and individuals in two automobiles fled in opposite directions as soon as they spotted police.
The vehicles' occupants opened fire when officers chased them, the secretariat said.
Two suspects in one of the vehicles were killed and a third was arrested, while two suspects died in the other vehicle and two others were arrested, the secretariat said.
Another shootout occurred at the ranch house, leaving five suspects dead and five others under arrest, officials said.
Police seized two 12-gauge shotguns, a machine gun, seven pistols, four revolvers, dynamite, a grenade and 20 kilos of marijuana from the suspects, the secretariat said.
An unidentified woman and child were found at the ranch, officials said. EFE