“I understand that the arrests have been made as a result of investigations conducted by the relevant Canadian law enforcement agencies. This issue is internal to Canada and therefore we have no comments to offer in this regard,” Verma added.
The trio, all Indian nationals, were arrested in the city of Edmonton in Alberta on Friday, police said.
Nijjar, 45, was shot dead in June outside a Sikh temple in Surrey, a Vancouver suburb with a large Sikh population. A few months later, Canadian Prime Minister Justin Trudeau cited credible allegations of Indian government involvement, prompting a diplomatic crisis with New Delhi.
Nijjar was a Canadian citizen campaigning for the creation of Khalistan, an independent Sikh homeland carved out of India. The presence of Sikh separatist groups in Canada has long frustrated New Delhi, which had labelled Nijjar a “terrorist”.
Canadian police said they had worked with US law enforcement agencies, without giving additional details, and suggested more detentions might be coming.