OTTAWA: An advocate for Khalistan, a separate nation for Sikhs to be carved out of India's Punjab state through secession, was shot dead in Canada, police said Monday.

The secessionist, identified as Hardeep Singh Nijjar, 45, was wanted by Indian authorities.

Federal police said in a statement that Nijjar, who was not initially identified, was found in his pickup truck in the parking lot of the Guru Nanak Sikh Gurdwara temple in Surrey, British Columbia, around 8:30 pm on Sunday, "suffering from apparent gunshot wounds."

The Khalistan campaigner soon succumbed to his injuries, the Royal Canadian Mounted Police added.

As per the police, Nijjar was the temple's president who advocated for the creation of Khalistan.

The later police statement said they were releasing his identity "in hopes of advancing their investigation."

"We understand there is a lot of speculation regarding the motive of this homicide, but we are dedicated to learning the facts and letting the evidence lead our investigation," said Timothy Pierotti of the police's Integrated Homicide Investigation Team.

Nijjar was wanted by Indian authorities for alleged terrorism offences and conspiracy to commit murder, which he reportedly denied to Canadian media.

He had been warned by Canada's spy agency about threats against him, according to the World Sikh Organization of Canada, which said that he was "assassinated in a targeted shooting".

It pointed to the killings or suspicious deaths of other prominent Khalistan activists in recent months: Avtar Singh Khanda, in Britain, and Paramjit Singh Panjwar, in Pakistan.

India's Punjab state which is about 58% Sikh and 39% Hindu was rocked by a violent Khalistan separatist movement in the 1980s and early 1990s, in which thousands of people died.

Today, the separatist movement's most vocal advocates are primarily among the Punjabi diaspora.

India has often complained to foreign governments, including Ottawa, about the activities of Sikh separatists among the Indian diaspora who, it says, are trying to revive the insurgency.