The United States has filed charges against an Indian crime boss, alleging he helped orchestrate the political assassination of Sikh activist Hardeep Singh Nijjar in Canada—an episode that drove tensions between the two countries.

U.S. Attorney Bill Essayli announced the charges at a news conference in Los Angeles, saying the case involved a large joint law enforcement operation spanning U.S., Canadian and European agencies. Prosecutors said the sweep targeted alleged members of three Indian international crime syndicates, with 37 defendants arrested and additional fugitives still being sought.

Authorities accuse Lawrence Bishnoi, 33, and his childhood friend Satinderjeet Singh of playing key roles in the assassination of Nijjar, who was fatally shot outside a temple in 2023 where he served as president. Prosecutors say Bishnoi’s network “routinely targeted” prominent religious, social and political figures in exchange for money, and that the groups helped fuel violence and instability affecting East Indian communities in California and abroad.

The killing sparked a diplomatic crisis. After then-Canadian Prime Minister Justin Trudeau said there were “credible allegations” linking India to Nijjar’s death, Canada and India expelled diplomats and raised the issue at the highest levels.

As part of the broader investigation, prosecutors said the syndicates were also involved in other crimes including kidnappings, racketeering, extortion, firearms dealing and drug trafficking, along with murder. Authorities said investigators found the groups operated across multiple countries, including the United States, Canada and parts of Europe, with some allegations involving connections to corrupt officials in India.

Bishnoi is in custody, while prosecutors said Satinderjeet Singh has not been apprehended. Authorities also said they are searching for other fugitives in the U.S., India and Europe as the case proceeds.