New Delhiinfo-icon: Indiainfo-icon on Monday asked Canadian diplomats in New Delhi to leave the country by Saturday after Ottawa said it was investigating its Indian ambassador and other diplomats as "persons of interest", after the killing last year of a Sikh separatist leader.

In a tit-for-tat move, Canadainfo-icon too has asked six Indian diplomats to leave the country after its police collected evidence they were part of an Indian government "campaign of violence".

The 2023 murder of Canadian citizen Hardeep Singh Nijjar crashed the country's diplomatic relations with India after Prime Minister Justin Trudeau said there were "credible allegations" linking Indian intelligence services to the crime.

The expulsion of the diplomats -- the most senior envoys on both sides -- is a major escalation in the row.

India "decided to expel" Ottawa's acting High Commissioner Stewart Wheeler, his deputy and four first secretaries, ordering they leave before midnight on Sunday.

"The Government of India has decided to expel the following 6 Canadian Diplomats: Mr. Stewart Ross Wheeler, Acting High Commissioner; Mr. Patrick Hebert, Deputy High Commissioner; Ms. Marie Catherine Joly, First Secretary; Mr. lan Ross David Trites, First Secretary; Mr. Adam James Chuipka, First Secretary; Ms. Paula Orjuela, First Secretary. They have been asked to leave India by or before 11:59 PM on Saturday, October 19, 2024," the Ministry of External Affairs said in a press statement.

Ottawa announced similar measures in return, with Canadian police saying they had "evidence pertaining to agents of the government of India's involvement in serious criminal activity" in Canada.

Nijjar -- who immigrated to Canada in 1997 and became a citizen in 2015 -- had advocated for a separate Sikh state, known as Khalistan, carved out of India.He had been wanted by Indian authorities for alleged terrorism and conspiracy to commit murder.

Four Indian nationals have been arrested in connection with Nijjar's murder, which took place in the parking lot of a Sikh temple in Vancouver in June 2023.New Delhi had earlier said it had "received a diplomatic communication from Canada suggesting that the Indian High Commissioner and other diplomats are persons of interest" in the ongoing investigation.

It said their envoy, Sanjay Kumar Verma, a former ambassador to Japaninfo-icon and Sudaninfo-icon, was a respected career diplomat and that the accusations were "ludicrous."New Delhi's foreign ministry said it had told Verma to return home.

"We have no faith in the current Canadian Government's commitment to ensure their security," it said in a statement.

India on Monday called allegations it was connected to the killing "preposterous" and a "strategy of smearing India for political gains."

Last year, the Indian government briefly curbed visas for Canadians and forced Ottawa to withdraw diplomats, and on Monday threatened further action.

"India reserves the right to take further steps in response to the Trudeau Government's support for extremism, violence and separatism against India," the foreign ministry said.

The foreign ministry also summoned Canadian envoy Wheeler, who said that Ottawa had given India the evidence it had demanded."Canada has provided credible, irrefutable evidence of ties between agents of the Government of India and the murder of a Canadian citizen on Canadian soil," Wheeler told reporters after leaving the ministry.

"Now, it is time for India to live up to what it said it would do and look into all those allegations. It is in the interest of both our countries and the peoples of our countries to get to the bottom of this. Canada stands ready to cooperate with India."

India then announced his expulsion.

Canada is home to around 770,000 Sikhs, who make up about two percent of the country's population, with a vocal minority calling for an independent state of Khalistan.

In November 2023, the USinfo-icon Justice Department also charged an Indian citizen living in the Czech Republic with allegedly plotting a similar assassination attempt on US soil.Prosecutors said in unsealed courtinfo-icon documents that an Indian government official was also involved in the planning of that attempt.

Diplomatic strain hits airlines

Airlines, which have already been impacted by Canada's issuance of fewer student visas, are bracing for a tough winter following a strain in ties between India and the North American country.

Over 2.2 million passengers flew between the two countries in CY 2023. Air Canada and Air India are the largest carriers in the marketinfo-icon and accounted for 45 per cent of traffic last year. 

Fresh capacity is being added to the market in the winter schedule, intensifying competition.

Air India is adding three extra flights between Delhi and Toronto from November 1, making it a double-daily service. In June, Air Canada announced the reintroduction of its winter seasonal flight to Mumbaiinfo-icon and the launch of a one-stop flight between Calgary and Delhi via London.

Canada is also the fifth largest source market for tourism in India, accounting for 4 per cent of all arrivals in CY 2023. However, that largely consists of Canadian citizens of Indian origin visiting friends and families in India.