TORONTO — India has told Canada to remove 41 of its 62 diplomats in the country by Oct 10, an official familiar with the matter said on Tuesday, ramping up confrontation between the two countries over Canadian accusations that India was involved in the killing of a Sikh leader in suburban Vancouver.

The official, who confirmed an earlier report from the Financial Times, spoke on condition of anonymity.

Last month, Canadian Prime Minister Justin Trudeau said there were "credible allegations" of Indian involvement in the slaying of Hardeep Singh Nijjar, a 45-year-old Sikh leader who was killed by masked gunmen in June. For years, India has said Nijjar, a Canadian citizen born in India, has links to terrorism, an allegation Nijjar denied.

Arranging the killing of a Canadian citizen in Canada, home to nearly 2 million people of Indian descent, would be unprecedented. India has denied the claim.

On Tuesday, Trudeau did not confirm the number of diplomats that have been told to leave, but suggested Canada would not retaliate.

Canadian Foreign Minister Melanie Joly said: "We will continue to engage privately because we think that diplomatic conversations are best when they remain private."

India has accused Canada for years of giving free rein to Sikh separatists, including Nijjar.

India has also canceled visas for Canadians. Canada has not retaliated for that. India previously expelled a senior Canadian diplomat after Canada expelled a senior Indian diplomat.

Trudeau has also previously appeared to try to calm the clash, saying Canada is "not looking to provoke or escalate".

The allegation of India's involvement in the killing is based in part on the surveillance of Indian diplomats in Canada, including intelligence provided by a major ally, a separate Canadian official previously told The Associated Press.