Canada killing adds to suspicions of Indian crackdown on Sikh separatists

Khalistani groups who want independence of Punjab accuse India of killings in UK and elsewhere

• Canada and India make tit-for-tat envoy expulsions over killing of Sikh leader

Months before Hardeep Singh Nijjar was shot dead in a car park in Canada, three other Indians associated with the Sikh separatist movement had died on foreign soil - in circumstances deemed, at least by some, as suspicious.

On Monday, Justin Trudeau alleged there was credible evidence" that the Indian government was behind the assassination of Nijjar, an explosive accusation that torpedoed already frayed diplomatic relations between India and Canada. India called the allegation absurd" and both sides expelled senior diplomats in response.