Militants torched five trucks transporting NATO equipment from Afghanistan in the restive Balochistan province of southwest Pakistan, security officials said.
The container trucks were set ablaze in Kambiri area of Bolan district by four masked militants on motorbikes, officials of the Levies militia told the media.
"Five NATO trucks were carrying NATO equipment back. Gunmen first fired on the first vehicle and then sprinkled petrol on all of them," a senior government official said.
The trucks were carrying NATO supplies from Afghanistan to the port city of Karachi as the alliance prepares for ending its combat mission there by 2014.
The militants on motorbikes fired at the vehicles forcing them to stop and then doused petrol on the trucks before setting them on fire.
The trucks were destroyed though no one was injured in the attack, officials said. The incident occurred at a spot 120 kilometres from the provincial capital Quetta.
Levies personnel cordoned off the area after the incident and launched a search operation but were unable to trace the attackers.
No group has claimed responsibility for the attack.
NATO container trucks and fuel tankers have been targeted by militants in northwest and southwest Pakistan over the past few years.