Malik Mohammad Jan was part of an anti-Taliban militia raised with the help of government to fight the militants.
He and five others were travelling to Har area when an IED planted on the roadside went off in Mamond area of Bajaur, one of the seven tribal districts of Pakistan.
The bomb was detonated by a remote-control device, said an official. "Six people including a tribal chief were killed."
Nobody took responsibility for the attack but Taliban has often attacked pro-government leaders in the volatile region.