Police and health officials said an explosion had killed four people after a rally by Khan's Pakistan Tehreek-e-Insaf (PTI) party.

A court jailed Khan for leaking state secrets.

"Three workers of Tehreek-e-Insaf are martyred and 7 are injured," Provincial General Secretary Balochistan for PTI, Salar Khan Kakar, said in a video message shared on PTI's X account.

(Reporting by Saleem Ahmed, writing by Sakshi Dayal; Editing by YP Rajesh and Nick Macfie)