Former Khyber Pakhtunkhwa MPA Hashim Khan and two of his aides were gunned down in Lower Dir's Shah Alam Baba area on Thursday, police said.
Station House Officer (SHO) Fazal Mabood said unknown gunmen had opened fire on the vehicle in which Khan, a Jamiat-i-Ulema-i-Islam Fazl leader, was travelling, killing him and his two aides.
The bodies were shifted to a local hospital as police launched a search operation to arrest the gunmen, the SHO added.
Khyber Pakhtunkhwa has seen a number of security challenges in the past year.
Early last month, four personnel of the Pakistan Army, including a major, lost their lives while attempting to foil a terrorist attack in the Upper Dir area.
In February, the army had launched Operation Raddul Fasaad across the country with the aim of eliminating the latent threats of terrorism.