India on Wednesday advised all its citizens living in Canada and those contemplating travelling there to exercise "utmost caution" in view of growing anti-India activities and "politically-condoned" hate crimes in the North American country, as the diplomatic row over killing of a Khalistani separatist leader threatened to snowball into a major confrontation.

In a strongly-worded advisory, the Ministry of External Affairs (MEA) referred to "threats" targeting Indian diplomats and sections of the Indian community that oppose the "anti-India agenda", and asked Indian nationals to avoid travelling to regions and potential venues in Canada which have seen such incidents.

Prime Minister Justin Trudeau's allegations of a "potential" involvement of Indian government agents in the killing of Khalistani separatist Hardeep Singh Nijjar in June unleashed a diplomatic row with India rejecting the charges as "absurd" and "motivated" and kicking out a senior Canadian diplomat in a tit-for-tat move to Ottawa's expulsion of an Indian official.

In the advisory, the MEA asked Indian students in Canada to exercise extreme caution and remain vigilant.

It is also learnt that India is in touch with a number of its strategic partners in the West over the issue.

"In view of growing anti-India activities and politically-condoned hate crimes and criminal violence in Canada, all Indian nationals there and those contemplating travel are urged to exercise utmost caution," the MEA said in the advisory, in an indication of hardening of New Delhi's position on the row.

"Recently, threats have particularly targeted Indian diplomats and sections of the Indian community who oppose the anti-India agenda. Indian nationals are, therefore, advised to avoid travelling to regions and potential venues in Canada that have seen such incidents," it said.

The India-Canada ties came under some strain for the last few months in view of increasing activities of the pro-Khalistani elements in the North American country. India believes the Trudeau government is not addressing its genuine concerns.

Separately, Col. Todd Braithwaite, the Defence Attache at the Canadian High Commission in New Delhi, told PTI that Canada's Deputy Army Chief Major General Peter Scott is scheduled to visit India next week to attend a military conference.

"We will continue our military cooperation. It (the diplomatic row) is not going to impact (the defence relations). Our Deputy Army Chief will visit India to participate in the conference," he said when asked whether the escalating diplomatic row would impact the bilateral military ties.

In an explosive statement in the House of Commons on Monday, Trudeau said Canada was looking at "credible allegations potentially linking" Indian agents to the killing of Nijjar, a Canadian Khalistani terrorist. He was shot dead by two gunmen in Surrey on June 18.

The MEA on Tuesday trashed Trudeau's comments asserting that "such unsubstantiated allegations seek to shift the focus from Khalistani terrorists and extremists, who have been provided shelter in Canada and continue to threaten India's sovereignty and territorial integrity." At a think-tank event in Delhi, US Ambassador Eric Garcetti, replying to a question on the India-Canada diplomatic row, said any allegation "like this should be troubling".

"It is an active criminal investigation. I hope that we can make sure that perpetrators are brought to justice, and that they can all allow the space for that information and that investigation before anybody, leaps to any judgment," he said.

Following the deepening diplomatic crisis, Australia, the US and the UK, Canada's allies in the 'Five Eyes' intelligence-sharing framework expressed concern.

"Look, these are concerning reports, and I note that investigations are still underway, but obviously these are concerning reports, and as I've said, we are monitoring these developments closely with our partners, and we'll continue to do so," Australian Foreign Minister Penny Wong Wong told a press conference in New York on Tuesday.

In response to a question whether Australia has raised the issue with India, Wong said, “We have, Australia has raised these issues with our Indian counterparts, as you would expect us to do.” She added that Australia has been "monitoring these developments with partners closely, we will continue to do so, and I will confirm that we have raised our concerns with India. I'm not going to go into any further detail on that." Terming Trudeau's allegations as "very serious”, a top US official said Washington supports Ottawa's efforts to investigate the matter and encourages New Delhi to cooperate.

"I'm going to protect diplomatic conversations and I'll leave it at that. Certainly the President is mindful of these serious allegations, and they are very serious. And we support Canada's efforts to investigate this," US National Security Council (NSC) Coordinator for Strategic Communications John Kirby said.

"We believe a fully transparent comprehensive investigation is the right approach so that we can all know exactly what happened and of course, we encourage India to cooperate with that,” Kirby said in an interview to CNN.