A police officer in Phoenix, Arizona, shot to death an unarmed black man during a struggle and authorities said the officer believed the individual had a gun, in the latest fatal incident amid national turmoil over the policing of black communities.

On Thursday night, some 200 demonstrators protested against the killing of 34-year-old Rumain Brisbon, marching to Phoenix police headquarters and blocking streets, broadcaster CBS5 reported.

The Phoenix Police Department said Brisbon was sitting in a SUV outside a convenience store on Tuesday evening, and two witnesses told the officer the occupants of the vehicle were selling drugs.