A BLOODY police crackdown on alleged drug traffickers in a Rio de Janeiro slum that left 25 people dead was condemned today by residents, activists and the United Nations.

Two hundred officers and a helicopter carrying a sniper were involved in the operation in Jacarezinho, one of the Brazilian city’s biggest slums, which began early Thursday. The police suffered one fatality.

Residents said that officers had killed suspects who were trying to surrender and entered homes without a warrant.

Shortly after the shooting died down today, protesters gathered outside the police headquarters near Jacarezinho to denounce the violence, holding a banner reading: “Stop killing us!”

One resident told the Associated Press news agency that a man had barged into her home at about 8am bleeding from a gunshot wound. He hid in her eight-year-old daughter’s room, but the police came rushing in just behind him.

She said that she and her family had seen officers shoot the unarmed man.

Detective Felipe Curi of Rio’s civil police denied that there had been any executions.

He said: “There were no suspects killed. They were all traffickers or criminals who tried to take the lives of our police officers and there was no other alternative.”

The administration of Rio state Governor Claudio Castro, an ally of far-right President Jair Bolsonaro, said in a statement that it lamented the deaths, but that the operation had been “oriented by long and detailed investigative and intelligence work that took months.”

But former president Luiz Inacio Lula da Silva argued that any operation that produces two dozen deaths does not qualify as public security.

“That is the absence of a government that offers education and jobs, the cause of a great deal of violence,” said Mr da Silva, who is expected to challenge Mr Bolsonaro for the presidency next year.

Human Rights Watch and Amnesty International urged prosecutors to thoroughly investigate the operation.

“It’s completely unacceptable that security forces keep committing grave human rights violations such as those in Jacarezinho against residents of the favelas, who are mostly black and live in poverty,” said Amnesty executive director for Brazil Jurema Werneck.

“Even if the victims were suspected of criminal association, which has not been proven, summary executions of this kind are entirely unjustifiable.”

The UN human rights office called for an independent investigation, saying the crackdown was part of a “long-standing trend of unnecessary and disproportionate” police operations against predominantly poor communities.