A minimum of 64 civilians died in a law enforcement action against the criminal organization Comando Vermelho in Rio de Janeiro's northern suburbs - the most extensive and fatal action in the area's history.
Four police officers lost their lives during Operation Containment in the Alemão and Penha districts, state officials said. More than 80 suspects were detained.
Violent conflicts commenced when approximately 2,500 police forces entered the area on Tuesday early hours. The Comando Vermelho countered with armed resistance, setting fire to barriers and dropping bombs from drones, officials said.
The United Nations human rights body expressed being "shocked" by the police operation, calling for "swift and comprehensive examinations".
The slum neighborhoods near the aerial transportation hub is seen as the central command of among the nation's strongest illegal networks.
Government representatives confirmed at least 50 of the fatalities were "indicated by police as suspected of being criminals".
Dozens of people were hurt, including non-combatants affected by the violence.
Community members have described the hillside area - housing around 300,000 residents - to a "combat area" since the raid started.
Access ways continue shut in the entire neighborhood.
The Comando Vermelho organization has been increasing their control throughout the region, increasing drug trafficking routes and power in the informal settlements.
Rio's police reported more than 200kg (441lb) of illegal substances were confiscated in the raid, in addition to dozens of firearms.
The combined action by different law enforcement agencies was preceded by a twelve-month inquiry.
Numerous alleged criminals are considered participants in an organization from the Brazilian state who are currently hiding in the metropolitan area.
Extensive security missions are frequent in the country ahead of important worldwide conferences in the country.
The international environmental meeting the environmental summit is taking place in the city of Belem in the north in the eleventh month.
Elara is a seasoned strategist with over a decade of experience in corporate leadership and military tactics.