Indian Prime Minister Narendra Modi is focussed on combating Sikh separatism, despite its scant support among the country's small religious minority, due to security and political concerns, officials and experts say.

The movement for a Sikh homeland in northern India, crushed decades ago, has burst onto the global stage in recent months as the United States and Canada accused Indian officials of involvement in assassination plots against Sikh separatist leaders in North America.

New Delhi denies any connection to a June murder in a Vancouver suburb but has announced an investigation into U.S. concerns about an alleged plot in New York. It says such plots were not government policy and it is not hunting down Sikh separatists abroad.

The diplomatic dust-ups with normally friendly Washington and Ottawa highlight the outsized role Sikh separatism plays in the political calculus of Modi's Hindu-nationalist government, which is in a strong position to win national elections next year.

Indian security officials say they must crack down on what they call Sikh connections to crime overseas linked to the Sikh heartland of Punjab. Sikh nationalists reject that claim, saying Modi is trying to destroy their leadership and mobilise his Hindu base.

Other Modi critics say he is exploiting the issue for political gain after Sikh farmers dealt his government one of its biggest blows by forcing a rollback of agricultural reforms.

Sikh separatists demand that a homeland called Khalistan - "the land of the pure" - be carved out of Punjab, where their religion was founded around the end of the 15th century, and the only Indian state where they form a majority. Sikhs comprise fewer than 2% of India's 1.4 billion people.

A Khalistan insurgency killed tens of thousands in the 1980s and 1990s before it was put down by New Delhi and ceased to be a significant issue domestically.

Dead horse or mad dog?

"Khalistan has no ground support in Punjab today," said a senior Indian security official, but some prominent separatist leaders abroad "are involved in drugs, gun-running, crime syndicates and have links to Punjab too".

A recently retired top Indian security official called Khalistan a "dead horse" but insisted "you have to act to pre-empt" as they are raising money abroad, training people and agitating for India’s division.

India "has to be careful", he said, because issues are "boiling under the surface", including unemployment and rampant drug use in Punjab, which borders on India's archrival Pakistan.

Both officials asked not to be named given the current sensitivity of the issue.

India has not publicly released any recent evidence of Sikh separatist involvement with overseas crime, but New Delhi says it has repeatedly shared such evidence with foreign capitals.

An aggressive national security posture is an important element of Modi’s cultivated strongman image, built on actions including air strikes against Pakistan, ending special privileges for the disputed Kashmir region and targeting left-wing activists the government says are linked to Maoist militants.

Kanwarpal Singh, political secretary of the Punjab-based Dal Khalsa group, which lobbies for a separate Khalistan, rejected links to drugs or crime. Modi's government is seeking to "defame, isolate and eliminate" Sikh separatist leaders, he said.

The policy is to "call the dog mad and shoot him", he said.

Other critics of Modi's Bharatiya Janata Party (BJP), which has failed to make political inroads among Sikhs, accuse it of exaggerating the Khalistan problem for political gain.

"It is exploiting whatever limited Khalistani element there is in the country or in the diaspora to mobilise the Hindu population," said security expert Ajai Sahni.

Dal Khalsa's Singh said that after the yearlong 2021 farm protests by mostly Sikh farmers and activists bruised the BJP politically, "they are taking revenge on the Sikh community".