At least 22 people, including two police officers, were killed during a massive predawn police operation targeting organized crime in Rio de Janeiro's Alemão and Penha favela complexes on Tuesday.
The raids, involving over 2,500 security personnel and 32 armored vehicles, erupted into intense gunfights shortly after 4 a.m., disrupting life in the densely populated settlements home to around 300,000 residents.
Authorities described the action as the largest ever against the Comando Vermelho gang, with 80 arrests made and more than 40 automatic rifles seized as part of serving 250 warrants.
Governor Cláudio Castro announced the operation on social media, declaring the city "at war" and labeling the threat "narco-terrorism."
For the first time, traffickers reportedly deployed weaponised drones to drop explosives on advancing forces, escalating the violence.
Eight officers and four residents sustained gunshot wounds, while clashes forced the rerouting of bus services and halted operations at about 50 health and education facilities.
Security Secretary Victor Santos called it "Operation Containment," aimed at capturing gang members who control swaths of Rio and extend influence to regions like the Amazon.
The timing coincides with Rio's preparations to host the C40 summit of global mayors and Prince William's Earthshot Prize next week, events leading into the COP30 UN climate summit in Belém from November 10 to 21.
Such large-scale operations are routine before major international gatherings in Rio, which has previously secured the 2014 World Cup, 2016 Olympics, 2024 G20, and this year's BRICS summit.
Human rights activists and opposition figures decried the raids as excessive.
"This doesn’t solve the problem," said Rene Silva, a community journalist from Alemão.
State congressperson Lucia Marina dos Santos tweeted that the actions constituted a "state-sponsored massacre," turning favelas into war zones.
With skirmishes persisting into the afternoon, the death toll may climb, evoking memories of the 2021 Jacarezinho raid that claimed 28 lives.
Governor Castro placed police on high alert against potential reprisals, as criminals attempted to block key roadways.
This is a developing story and will be updated.