India said Thursday that Canada has shared no evidence to back its allegation that the Indian government was involved in the slaying of a Sikh separatist leader in Canada last year, despite the recent arrests of three Indian men in the crime.

India’s External Affairs Ministry spokesman Randhir Jaiswal also reiterated India’s longstanding allegation that Canada harbors Indian extremists.

Three Indian nationals who had been living in Canada temporarily were arrested on Tuesday in the slaying last June of Hardeep Singh Nijjar in British Columbia. Canadian Prime Minister Justin Trudeau had set off a diplomatic spat with India last September when he cited “credible allegations” of India’s involvement in the slaying of the Sikh separatist. India rejected the accusations.

Canadian Mounted Police Superintendent Mandeep Mooker said after the men's arrests that the investigation into whether they had ties to India’s government was ongoing.

Jaiswal said the two governments are discussing the case but that Canada has forwarded no specific evidence of the Indian government’s involvement.

Meanwhile, Jaiswal said New Delhi has complained to Canadian authorities that separatists, extremists and those advocating violence against India have been allowed entry and residency in Canada. “Many of our extradition requests are pending,” he said.

“Our diplomats have been threatened with impunity and obstructed in their performance of duties,” Jaiswal added. “We are having discussions at the diplomatic level on all these matters,” he said.

The three Indian men arrested in Canada haven’t yet sought any access to the Indian diplomats there, Jaiswal said.

The three — Kamalpreet Singh, 22, Karan Brar, 22, and Karanpreet Singh, 28 — appeared in court Tuesday via a video link and agreed to a trial in English. They were ordered to appear in British Columbia Provincial Court again on May 21.

They were arrested last week in Edmonton, Alberta. They have been charged with first-degree murder and conspiracy to commit murder.