RIO DE JANEIRO (AP) — Brazilian police say three people were killed in a turf battle between criminal gangs in Rio de Janeiro.

Authorities said Friday that six people were also injured in the shootouts that broke out Thursday evening in the city's Pedreira slum.

Seven buses were burned during the violence, which forced pedestrians to seek cover in a nearby subway station.

Wilson Witzel, governor of the state of Rio de Janeiro, says armed gangs use civilians as a "shield" and that authorities will not relent in efforts to fight crime.

Witzel, an ally of President Jair Bolsonaro, has faced criticism for an increase in deaths during police operations. He defends police tactics, saying they must have a freer hand to fight high levels of violent crime.