Bodies from a Rio de Janeiro police raid that left more than 20 alleged drug traffickers dead show signs of torture and summary execution, a senior lawyer said on Thursday, the latest incident of suspected police brutality to shock the South American nation.

Police say they encountered heavy gunfire when they carried out a raid in the slum of Vila Cruzeiro on Tuesday, an operation aimed at tracking down gang leaders who were allegedly hiding out there.

Evidence from the scene has raised concerns that some of the dead were tortured and killed in cold blood, according to Rodrigo Mondego, the head of the human rights commission at Rio's Bar Association.

"We saw one body with a white powder that looked like cocaine covering its face," he told AFP. "Whoever killed this person smeared it all over his face and may have forced him to eat it. It's an act of torture."

Police say they encountered gunfire during the raid on Vila Cruzeiro, but senior rights lawyer Rodrigo Mondego said he suspects 'a large number of summary executions.' Police say they encountered gunfire during the raid on Vila Cruzeiro, but senior rights lawyer Rodrigo Mondego said he suspects 'a large number of summary executions.' Photo: AFP / MAURO PIMENTEL

Mondego said there were suspicions of "a large number of summary executions."

"Witnesses have told us men who had surrendered to the police were then shot in the woods" above the hillside slum, he added.

The operation left at least 26 people dead, including a hairdresser hit by a stray bullet, according to the latest toll from health authorities.

The police operation left at least 26 people dead, including a hairdresser who was hit by a stray bullet, health authorities say The police operation left at least 26 people dead, including a hairdresser who was hit by a stray bullet, health authorities say Photo: AFP / MAURO PIMENTEL

Police put the death toll at 23.

Mondego said the number raised concerns about possible summary executions.

"If you look at statistics from around the world, you'll never see a firefight where more than 20 people are killed on one side and none on the other," he said.

Brazilian prosecutors have opened an investigation into possible human rights violations during the operation.

It was the second-deadliest such raid in Rio history, after another in May 2021 that left 28 people dead -- 27 alleged drug traffickers and one policeman -- in the slum of Jacarezinho.

At least 6,100 people were killed in police operations in Brazil in 2021, according to a violence monitoring group At least 6,100 people were killed in police operations in Brazil in 2021, according to a violence monitoring group Photo: AFP / ANDRE BORGES

President Jair Bolsonaro said Tuesday the police involved in the latest operation were "warriors" who had "neutralized at least 20 delinquents."

Human Rights Watch released a statement expressing concern at the violence and at Bolsonaro's comments.

"His message to police was clear: You can continue killing with impunity," said the US-based rights group in a statement on Thursday.

In the northeastern town of Umbauba, a man suffocated to death on Wednesday after being placed inside a police car trunk from which thick smoke was billowing.

The Federal Highway Police (PRF) said in a statement Thursday that its agents had "used immobilization techniques and instruments of low-offensive potential" in dealing with 38-year-old Genivaldo de Jesus Santos, who they said became aggressive during a routine stop.

A witness video shows two helmeted PRF officers trying to close the trunk lid on a man whose legs were still sticking out of it.

Thick white smoke, which appears to be from a tear gas canister, billows out of the trunk as the man cries out in pain.

A witness can be heard exclaiming: "They will kill him!"

The man is seen moving his legs for about a minute, and then goes motionless. The officers bend his legs and close the trunk.

According to the PRF, de Jesus Santos was taken to the Umbauba police station, but "felt unwell" during the journey and was taken to hospital.

The statement did not specify whether he arrived dead at the hospital, but an autopsy confirmed his death was by "asphyxiation."

Brazil's police are among the world's deadliest law enforcement forces, killing more than 6,100 people in operations in 2021, with 183 officers murdered, according to figures from a violence monitoring organization.