Nato supply lorries set ablaze by gunmen in Pakistan

A driver died in the ambush near the south-western city of Quetta.

The number of attacks on tankers has soared in the last week since one of the main routes into Afghanistan was shut by the Pakistani authorities.

The Torkham crossing was closed after three Pakistani soldiers died in a Nato air strike near the Afghan border.

Islamabad has not yet said when the Khyber Pass crossing will reopen.

In Wednesday morning's attack, up to 14 gunmen in two pick-up trucks opened fire on the tankers as they were parked by the roadside on the outskirts of Quetta, said police.

The lorries were thought to have been en route to a smaller border crossing into Afghanistan that still remains open.

The Pakistani Taliban reportedly said they carried out the ambush - the fourth attack on a Nato supply convoy in six days.

Spokesman Azam Tariq said: "We will further intensify attacks with the intensification of US drone strikes on us."

Unmanned aircraft have recently been targeting militants near the Afghan border on an almost daily basis.

Quetta's chief of police operations, Hamid Shakeel, said: "Gunmen came in two vehicles at daybreak and started firing. This created a stampede and people started running.

"Then one of the vehicles went [inside the compound] and they sprinkled petrol on trucks and set them on fire."

Mr Shakeel said that security for the trucks was the responsibility of local police while the vehicles were moving. But when they are parked at terminals, protection is the job of private contractors, he added.

On Tuesday, a bomb damaged an oil tanker in the Khyber tribal region. And on Friday, nearly 30 Nato supply lorries were set on fire in the southern province of Sindh.

Nato says the trucks passing through Pakistan carry fuel, military vehicles, spare parts, clothing and other non-lethal supplies for foreign troops in Afghanistan.

The closure of the Torkham border post has strained relations between Pakistan and the US.

The Nato-led International Security Assistance Force said on Monday its operations were so far unaffected by the attacks, but that it was "beginning to explore other options".

Supplies can also be brought into northern Afghanistan via Uzbekistan and Tajikistan.

Pakistan's other main crossing used by Nato into Afghanistan - Chaman in Balochistan - remains open, but this is not as convenient for supplies bound for Kabul.