All three individuals were arrested and charged with first-degree murder and conspiracy to commit murder.

Canadian police said Friday that they have arrested and charged three Indian nationals over the 2023 fatal shooting of prominent Sikh-Canadian activist Hardeep Singh Nijjar, which sparked a major diplomatic row between the two countries.

Nijjar, a 45-year-old Sikh separatist leader in Canada, was shot dead on June 18 last year by masked gunmen in a busy car park outside Vancouver.

The diplomatic row escalated after Canadian Prime Minister Justin Trudeau alleged in September that Indian government agents may have been involved in the killing.

India had accused Nijjar of links to terrorism, but angrily denied involvement in his slaying. In response to the allegations, India told Canada last year to remove 41 of its 62 diplomats in the country. Tensions remain but have somewhat eased since.

In announcing the arrests on Friday, Royal Canadian Mounted Police (RCMP) Superintendent Mandeep Mooker identified the three Indian nationals in their 20s as Kamalpreet Singh, Karan Brar, and Karampreet Singh.

All three individuals were arrested in Edmonton, Alberta, on Friday morning and charged with first-degree murder and conspiracy to commit murder, Mooker told reporters.

The suspects had been living in Canada as non-permanent residents.

“This investigation does not end here. We are aware that others may have played a role in this homicide, and we remain dedicated to finding and arresting each one of these individuals,” Mooker said.

“We are investigating whether there are any ties to the government of India,” he said, noting that it was an “ongoing investigation.”

RCMP Assistant Commissioner David Teboul said: “There are separate and distinct investigations ongoing into these matters. Certainly not limited to the involvement of the people arrested today.”

He said Canadian authorities are speaking to counterparts in India. “I would characterise that collaboration as rather challenging. It’s been very difficult.”

Nijjar, an Indian-born citizen of Canada, was a plumber and also a leader in what remains of a once-strong movement to create an independent Sikh homeland, known as Khalistan, in the Punjab region of India. But he had denied allegations of ties to terrorism.

Those close to the activist have said he was warned by Canadian intelligence services before his death that he was on a “hit list” and there had been threats on his life.

A bloody decades-long Sikh insurgency shook north India in the 1970s and 1980s, until it was crushed in a government crackdown that saw thousands of people killed, including prominent Sikh leaders.

The Khalistan movement has lost much of its political power but still has supporters in the Indian state of Punjab, as well as in countries with large Sikh populations.