Local activist Raull Santiago said he was part of a team that found about 15 bodies before dawn.

“We saw executed people: shot in the back, shots to the head, stab wounds, people tied up. This level of brutality, the hatred spread – there’s no other way to describe it except as a massacre,” Santiago said.

Castro said on Tuesday that Rio was at war against “narco-terrorism,” a term that echoed the Trump administration in its campaign against drug smuggling in Latin America. Rio’s state government said that those who had been killed had resisted police action.