STORY: Tactical teams from Rio de Janeiro's civil and military police raided the Alemao complex to take down an alleged criminal organization. The group was suspected of involvement in cargo theft and bank robberies and was planning incursions into rival slums, the military police said in a statement.
At least 18 people died in the raid: one police officer, 16 alleged criminals and a female bystander, police said. The operation involved around 400 officers, four aircraft and 10 armored vehicles.
The lopsided death toll ignited fears of rights abuses.
"There are signs of major human rights violations, and the possibility of this being one of the operations with the highest number of deaths in Rio de Janeiro," the state public defender's office said in a statement.
The military police declined to comment beyond their statement.
Rio state police forces regularly carry out deadly raids in the city's sprawling slums.
President Jair Bolsonaro supports heavy-handed tactics by police in their fight against organized crime, and has said gangsters should "die like cockroaches."
"It is similar to when we watched cowboy movies in the past, whenever someone committed a crime in the United States and ran away," the president said in his weekly Facebook broadcast.
After the raid, locals could be seen bundling injured people into the back of vehicles to be taken to hospital as police watched. Gilberto Santiago Lopes, from the Anacrim Human Rights Commission, said police refused to help.