The blast occurred at 2 a.m. at Khushali Tor Khel area of Waziristan killing the owner of the car and his guest. Motives behind the blast are not clear.

The authorities have confirmed the incident but did not say if it was an act of terrorism or the result of personal enmity.

Four people were killed yesterday in South Waziristan tribal region when they were trying to dismantle an artillery shell, thought to be used by Pakistani troops in operation against militants.

Officials believe hundreds of al-Qaeda suspects are hiding in the tribal region, who have fled the US-led operation in neighbouring Afghanistan.