India has been upset about frequent demonstrations and alleged vandalism by Sikh separatists and their supporters at Indian diplomatic missions in Canada, and has sought better security from the government.

Source: https://globalnews.ca/news/9975867/india-nijjar-visa-high-commission/

While violence is now rare and it has been years since the active insurgency ended, the Indian government has warned repeatedly that Sikh separatists were trying to make a comeback.

Source: https://www.mymotherlode.com/news/world/3230077/canada-expels-indian-diplomat-as-it-probes-possible-link-to-sikhs-slaying-india-rejects-allegation.html