Canadian Prime Minister Justin Trudeau said on Monday the Government of India may have carried out the murder of Sikh community leader and gurdwara president Hardeep Singh Nijjar, who was gunned down on June 18 in the parking lot of his Surrey, British Columbia place of worship.  Nijjar advocated for the establishment of an independent Sikh state called “Khalistan” in the Indian state of Punjab, where Sikhs are the religious majority.

Trudeau addressed the House of Commons, announcing that Canadian intelligence agencies are exploring “credible allegations of a potential link” between India’s government and the killing of Nijjar, who was 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. It is contrary to the fundamental rules by which free, open and democratic societies conduct themselves,” Trudeau said.

During his speech, Trudeau reported that he confronted Indian Prime Minister Narendra Modi with the accusations while the two leaders met during the G20 summit in New Delhi earlier this month. The Canadian PM said that his government will take “all steps” to hold those responsible for the murder accountable and called on the Indian government to cooperate in the ongoing investigation into Nijjar’s killing.

Canadian Foreign Affairs Minister Melanie Jolie added that a “top Indian diplomat” was expelled from Canada in response to the allegations.

New Democratic Party leader Jagmeet Singh, who is Sikh, reacted to Trudeau’s announcement, saying:

I grew up hearing that if you raised concerns about human rights violations in India, then you might be denied a visa, that if you went back to India, you could suffer violence, torture and even death. I grew up hearing those stories, but to hear the Prime Minister of Canada corroborate a potential link between a murder of a Canadian citizen on Canadian soil by a foreign government is something that I could never have imagined.

Indian authorities have previously claimed Nijjar led a terrorist group called “Khalistan Tiger Force,” which they say was responsible for a 2007 cinema bombing in Punjab. Nijjar had previously been the subject of a 2014 Interpol red notice issued by India in relation to the bombing. In 2016 Indian intelligence agencies also accused Nijjar of operating a terror camp in British Columbia to carry out attacks in Punjab. Nijjar denied the accusations.

Tensions have remained high between India’s government and Khalistan separatists. During this month’s G20 summit, Modi took issue with ongoing pro-Khalistan protests in Canada while meeting Trudeau.  In July, one person was arrested outside the Indian consulate in Toronto during a protest and counter-protest following Nijjar’s death. During the dueling demonstrations, Khalistan activists accused India of being behind the killing, while pro-India counter-protesters labeled the rallying Khalistan supporters extremists.

In April, Indian authorities arrested Sikh separatist Amritpal Singh on charges of attempted murder following a 35-day manhunt which saw internet service temporarily suspended in Punjab. The Indian government also summoned Canada’s High Commissioner to India one month prior to his arrest following a protest outside India’s Vancouver consulate in support of Amritpal Singh and against Punjab’s internet blackout.

There is currently an unofficial global referendum organized by the US-based Sikhs for Justice group asking whether Sikhs want an independent Punjab. The referendum is ongoing.

Neither Modi nor the Indian government has responded to Trudeau’s statements at the time of publication.