In video messages, released on November 4, Pannun had asked Sikhs to stop flying on Air India planes on and after November 19, citing a potential threat to their lives.
A diplomatic firestorm erupted this week with Canadian PM Justin Trudeau saying there were "credible reasons to believe that agents of the government of India were involved" in Nijjar's death.
Pannun, a Khalistani separatist and designated terrorist, called for a complete shutdown of CRPF schools on October 26 in Nagpur, Delhi, Sonipat, Pinjore and Jalandhar.