A group of unidentified armed men opened fire on two tankers in Quetta — the provincial capital of Baluchistan Province — on Thursday morning. At least one driver was killed in the shootout, Pakistani news television channel AAJ TV reported.
The assailants later torched the tankers and fled the area in a vehicle. Their whereabouts is unknown.
Police cordoned off the area after the incident and launched a search operation to arrest the perpetrators.
The attack came a day after one person was killed and two others sustained injuries as militants attacked two NATO fuel tankers in Landi Kotal district of the border town of Torkham.
Tehrik-i-Taliban Pakistan militants regularly attack NATO convoys in Pakistan.
The US military and NATO rely heavily on the Pakistani supply route into landlocked Afghanistan, more so now that Taliban attacks are increasing.
Supplies arrive by sea in the southern port city of Karachi, where security analysts believe most of the Afghan Taliban leadership is now hiding. From there, they must travel in long, exposed convoys, through Khyber Pakhtunkhwa province in northwest Pakistan.
Militants in the rugged tribal area have staged violent attacks in recent months, torching hundreds of NATO vehicles and containers destined for foreign troops in Afghanistan.
In response, the Pakistani authorities have deployed large contingents of police and military forces on all major arteries in the area to curb the attacks.
Other routes, largely through Russia and the Central Asian states, have proved too costly, both politically and economically.