US and NATO forces in Afghanistan get around 75 per cent of their food and military supplies through Pakistan [EPA]

Gunmen on motorbikes have attacked two NATO oil tankers, setting the vehicles ablaze in Pakistan's restive southwest, officials said.

Wednesday's attack took place near the town of Dadar in Bolan district, 90 kilometres southeast of Quetta, the capital of Baluchistan province, Abdul Aziz, local tribal police official told the AFP news agency.

Unknown gunmen on motorbikes signalled the vehicles to stop and opened fire when the driver ignored them, Aziz said. There were no casualties, he added.

The tankers were carrying oil for NATO forces in Afghanistan. Local intelligence officials confirmed the attack.

NATO supply trucks and oil tankers are targets of frequent attacks in Pakistan.

They are blamed on insurgents attempting to disrupt supplies for the 140,000 US-led international troops fighting the Taliban in neighbouring Afghanistan.

Most supplies and equipment required by coalition troops in Afghanistan are shipped through Pakistan, although US troops increasingly use alternative routes through central Asia.

Baluchistan, which borders Iran and Afghanistan, has suffers attacks by armed religious groups and an insurgency by rebels seeking political autonomy and a greater share of profits from natural resources.

Source: Agencies