Brazilian authorities say drug traffickers opened fire on police patrolling the streets near a shantytown in Rio de Janeiro, shooting six officers.

Authorities say the gang members used machine guns and even grenades to attack the officers as they drove by the Jacarezinho slum in northern Rio de Janeiro.

Police spokeswoman Vania Ferreira says the wounded officers were not in danger of dying.

Authorities say early Thursday's attack prompted nearby schools to suspend classes and temporarily halted service in a subway line.