Mourners react as people gather around bodies, the day after a deadly police operation against drug trafficking at the favela do Penha, in Rio de Janeiro, Brazil, October 29, 2025. REUTERS/Ricardo Moraes

BELEM, Brazil (Reuters) -Brazilian President Luiz Inacio Lula da Silva said on Tuesday his government will push for an independent probe into a police raid last week in Rio de Janeiro that killed 121 people, including four police officers.

"It's important to see under what conditions it happened," he told reporters in Belem ahead of the COP30 climate summit. "The judge's order was for arrest warrants to be served, not a mass killing - and yet there was a mass killing."

The operation on October 28 was the deadliest in Brazil's history. It targeted the Comando Vermelho gang that controls the drug trade in several favelas - poor, densely populated neighborhoods woven through the city's hilly terrain.

Rio de Janeiro state officials described it as a success. State Governor Claudio Castro said the "only real victims" were the slain officers and that all the others killed were criminals.

The raids underscored a complex political scenario for Lula, a leftist who has attempted to reconcile international concerns over human rights violations with growing public support for a crackdown on crime.

"The hard fact is that, in terms of the death toll, some may see the operation as a success. But from the standpoint of state action, I believe it was disastrous," Lula said.

(Reporting by Katy Daigle and Lisandra Paraguassu; Writing by Gabriel Araujo; Editing by Paul Simao)