One of the banks was located next to a police station.
“These criminals were prepared for war,” said Alvaro Batista Camilo, head of Sao Paulo state’s police force.
The would-be robbers drove up to the banks in five armored cars and were armed with high-caliber rifles and body armor, authorities said.
Police arrived at the banks and confronted the assailants, who fled and led police on a rolling shootout through the city of Guararema, located about 60 kilometers (37 miles) east of central metropolitan Sao Paulo.
The suspects broke into a home at one point and held the residents hostage, “but police managed to free them,” the secretariat said, without providing more details.
No police were injured during the operation.
Police commander Mario Silva told Globo TV that the criminal group was under surveillance, and that “we already knew they were going to carry out an attack in this area.
“We did not know exactly where the attack would take place,” Silva said. “But we increased police forces in the area over the past 24 hours.”
Far right President Jair Bolsonaro, who has publicly called for Brazil’s already lethal police force to carry out more killings of suspected criminals, praised the action.
“Eleven criminals were killed and not a single innocent was injured. Great work!” Bolsonaro tweeted.
