New Delhi - Canada's High Commission said Thursday it would 'adjust' the number of its diplomats in India after threats on social media against staff, as a diplomatic row with New Delhi escalates.

Canada's Prime Minister Justin Trudeau has demanded India treat with 'utmost seriousness' allegations that Indian agents played a role in the June murder of Hardeep Singh Nijjar near Vancouver.

The fallout prompted diplomatic expulsions and a forceful denial from India, which said any suggestion it played a role in Nijjar's killing was 'absurd.'

'In light of the current environment where tensions have heightened, we are taking action to ensure the safety of our diplomats,' Canada's mission said in a statement.

'With some diplomats having received threats on various social media platforms, Global Affairs Canada is assessing its staff complement in India,' it added.

'As a result, and out of an abundance of caution, we have decided to temporarily adjust staff presence in India.'

Earlier on Thursday, India's official visa processor in Canada said it had been told to stop handling applications.

Shortly after the announcement was splashed across Indian media, BLS International removed the notice from their website. There was no immediate comment from India's foreign ministry.

The suspension of visas comes a day after India's foreign ministry said it was concerned for the safety of its citizens in Canada because of 'politically-condoned hate crimes and criminal violence'.

'Threats have particularly targeted Indian diplomats and sections of the Indian community who oppose the anti-India agenda,' a ministry statement said Wednesday.

'Indian nationals are therefore advised to avoid traveling to regions and potential venues in Canada that have seen such incidents.'

The advisory did not name specific cities or locations for Indians to avoid.

Nijjar was shot dead by two masked assailants outside the Sikh temple he presided over in Surrey, an outer suburb of Vancouver.

An activist for the creation of a Sikh state known as Khalistan, Nijjar was wanted by Indian authorities for alleged terrorism and conspiracy to commit murder.

He had denied those charges, according to the World Sikh Organization of Canada, a nonprofit organization that says it defends the interests of Canadian Sikhs.

The Indian government accuses Ottawa of turning a blind eye to the activities of radical Sikh nationalists who advocate the creation of an independent Sikh state to be carved out of northern India.