Brazilian police raided a low-income neighborhood in Rio de Janeiro at sunrise, starting an hours-long gun battle with one of the most powerful criminal gangs in the country, resulting in 25 people dead, the Washington Post reports.

Dozens of heavily armed police officers, with the assistance of bulletproof helicopters and armored vehicles, raided the Jacarezinho favela to take down Comando Vermelho, or the Red Command, a criminal network that deals in guns and drugs.  Of the 25 killed, only one was reported to be a police officer.

“Really grim moment in Brazil,” said Robert Muggah, co-founder of the Igarapé Institute, a Rio-based think tank that tracks trends in violence. “These shootings are obviously routine in Rio de Janeiro, but this is unprecedented, in that it’s the operation that has generated the largest number of deaths, ever.”

Police said the raid was prompted by efforts of the Red Command to recruit children into their operations.  Photos of the scene show blood splattered walls and bodies piled in a room.  Police said gang members tried to defend their turf while others tried to flee while shooting.

Brazil is gripped in a spate of gang and police violence, one leading to increases in the other.  Recently, police have taken to bloody crackdowns on gangs around the nation, leading to many people questioning the police operations.  “A cop who doesn’t kill isn’t a cop,” President Jair Bolsonaro is quoted as saying when defending police actions.

“In this badly-planned operation a police officer was killed,” said Silvia Ramos, a social scientist at University Candido Mendes. “And this operation became one of revenge. And police simply killed more than 20 people.”