Police and researchers are calling the police raid in Brazil one of the deadliest police shootings in the history of Rio de Janeiro. The incident left at least 25 people killed, including one policeman.

The shootout happened during a police operation in a favela in the Jacarezinho area of the city after police received reports that drug traffickers were recruiting children to join their crime group, according to a BBC News report.

Police sent bulletproof helicopters, armored vehicles, as well as dozens of heavily armed police officers to attack the stronghold of the notorious criminal gang.

Residents stayed inside their homes, unable to leave. Children were also caught in the crossfire, according to The Washington Post report.

Robert Muggah, co-founder of the Igarapé Institute, said that the incident is a really dark moment in Brazil.

"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," Muggah was quoted in a report.

Igarapé Institute is a Rio-based think tank focusing on violence trends.

Police Chief Ronaldo Oliveira said that the Thursday police raid caused the largest number of deaths in a police operation in Rio.

One resident shared his sentiment, saying that he would try to move out of the area as soon as possible. He added that they cannot continue to live in the area.

Police were reported to seize some of the residents' phones, accusing civilians of warning gang members about the operation.

Meanwhile, suspects of the targeted drug gang were recorded in aerial footage trying to escape in Rio de Janeiro.

Police said in a statement that the suspects did not only plan to flee the area, but also to kill.

READ MORE: In Brazil, Police Shoot Civilians Without Restraints, Killed 1,814 in 2019 Alone

Police Violent Operations

The deadly police operations have been encouraged by a range of political leaders, who have managed to win recent elections by campaigning warlike strategies to curb crime and target gangs.

Brazilian President Jair Bolsonaro once said that a cop who does not kill is not a cop.

Rio de Janeiro is considered to be Brazil's one of the most violent states, with several of its areas under the control of organized crime groups.

Security forces in Brazil have been accused of excessive use of force on civilians.

Supreme Court has ruled to stop incursion during the COVID pandemic. However, raids remain to territories families with nearly 800 people were killed by police in Rio de Janeiro in the past nine months.

The court ruled to suspend police raids in Brazilian favelas in June 2020 after the death of 14-year-old João Pedro Matos Pinto, according to The Guardian report.

Pinto was one of the victims during a police raid. He was shot in the back in the middle of it.

Daniel Hirata, professor of sociology at Federal Fluminense University, said that the high court made a decision and political leaders do not respect it.

"This is a risk to the rule of law in Brazil," Hirata was quoted in a report.

READ NEXT: President Bolsonaro Sends National Troops to Control Nationwide Police Strikes

WATCH: Twenty-five killed in Rio de Janeiro police raid on drug gang - from Newzee