India has expelled a senior Canadian diplomat after PM Justin Trudeau suggested Delhi may have been involved in the murder of a Sikh separatist leader.
Earlier Canada's foreign minister announced an Indian diplomat was being expelled.
The escalating row centres on the murder of Hardeep Singh Nijjar, a Canadian citizen shot dead outside a Sikh temple on 18 June in British Columbia.
Trudeau said Canadian intelligence were pursuing "credible allegations" of a link between his death and the Indian state.
India has firmly rejected Trudeau's allegations, calling them "absurd" and politically motivated.
It added that Canada had long provided shelter to "Khalistani terrorists and extremists" who threaten India's security.
Nijjar had publicly campaigned for Khalistan - the creation of an independent Sikh homeland in the Punjab region of India.
With over 770,000 Sikhs, Canada is home to the largest Sikh diaspora outside the state of Punjab.
On 8 July, hundreds gathered to protest Hardeep Singh Nijjar's death in Toronto outside India's High Consulate building.
They were met with a smaller counter protest in support of the Indian government.
On Monday, Tejinder Singh Sidhu, president of the World Sikh Organisation of Canada, said: “India cannot be allowed to disregard the rule of law and the sovereignty of foreign states.
"The killing of Hardeep Singh Nijjar and other Sikh activists were terrorist acts that must be condemned by the international community."
Sidhu also called on India to honour its international obligations and cooperate with Canadian government over the investigation.
