NEW DELHI (AP) India expelled one of Canadas top diplomats Tuesday, ramping up a confrontation between the two countries over Canadian accusations that India may have been involved in the killing of a Sikh separatist leader in suburban Vancouver.

India, which has dismissed the accusations as absurd, said the expulsion came amid growing concern at the interference of Canadian diplomats in our internal matters and their involvement in anti-India activities, according to a statement from its Ministry of External Affairs.

Prime Minister Justin Trudeau appeared to try to calm the diplomatic clash Tuesday, telling reporters that Canada is not looking to provoke or escalate.

We are simply laying out the facts as we understand them and we want to work with the government of India to lay everything clear and to ensure there are proper processes, he said. India and the government of India needs to take this matter with the utmost seriousness.

On Monday, 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 in Surrey, outside Vancouver. For years, India has said Nijjar, a Canadian citizen born in India, has links to terrorism.

Canada has yet to provide any evidence of Indian involvement, but if true it would mark a major shift for India, whose security and intelligence branches have long been significant players in South Asia, and are suspected in a number of killings in Pakistan. But arranging a killing in Canada, home to nearly 2 million people of Indian descent, would be unprecedented.

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

The dueling expulsions have escalated tensions between Canada and India. Trudeau had frosty encounters with Indian Prime Minister Narendra Modi during this months Group of 20 meeting in New Delhi, and a few days later Canada canceled a trade mission to India planned for the fall.

Nijjar, a plumber, was also a leader in what remains of a once-strong movement to create an independent Sikh homeland , known as Khalistan. A bloody decade-long Sikh insurgency shook north India in the 1980s, until being crushed in a government crackdown in which thousands of people were 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 the sizable overseas Sikh diaspora. While violence is now rare and it has been years since the active insurgency ended, the Indian government has warned repeatedly that Sikh separatists were trying to make a comeback.

Nijjar was wanted by Indian authorities, who offered a reward for information leading to his arrest. Nijjar denied the allegations and was working with a group known as Sikhs For Justice to organize an unofficial Sikh diaspora referendum on independence from India at the time of his killing.

Gurpatwant Singh Pannun, a lawyer and spokesperson for Sikhs For Justice, has said Nijjar was warned by Canadian intelligence officials about being targeted for assassination by mercenaries.

Niijars son, Baraj Singh Nijjar, said Tuesday that his family and the Sikh community were relieved by the Canadian actions.

From day one we kind of had this idea and knowledge that if anything would happen to him, the Indian government would be involved, he said. It was just a matter of time for when the truth would come out. Its finally coming to the public eyes that the Indian government is involved in this.

On Monday, Trudeau told Parliament that Canadian security agencies were investigating credible allegations of a potential link between agents of the government of India and the killing of a Canadian citizen.

Any involvement of a foreign government in the killing of a Canadian citizen on Canadian soil is an unacceptable violation of our sovereignty, he said.