The incident took place earlier today in Tirah Valley after a remotely-controlled IED was detonated near a peace committee vehicle, the local officials said.
The Head of Peace Committee Zarwali Khan quoted in a report by local Dawn News said three members of the committee were killed in the explosion.
He said the deceased committee members have been identified as Noor Khan, Hameed Khan and Amir Nawaz.
According to the security sources, a levies officer identified as Abdul Manan was also among those killed.
No individual or group including Tehrik-e-Taliban Pakistan has so far claimed responsibility behind the incident.
This is not the first time the militant groups have carried out an attack in tribal areas of Pakistan.
At least ten people were killed after a vehicle struck a roadside bomb in Kurram Agency last month while 22 people were killed in a similar incident in the same area in the month of March.