Four suspected militants opened fire on a convoy of NATO fuel trucks in southwestern Pakistan. Attacks on NATO supply convoys have increased in recent weeks.

An attack on a NATO convoy.

A tanker caught fire on Wednesday when gunmen attacked at least seven NATO trucks near the town of Sibbi in southwestern Pakistan.

Eyewitnesses described how four men, two on motorcycles and two on foot, sprayed bullets at the convoy carrying fuel for NATO forces in Afghanistan.

Another truck was also damaged by gunfire while the remaining five escaped.

It is suspected that Islamist militants are responsible for the assault.

Attacks on convoys carrying supplies for NATO forces have increased since a cross-border air strike by NATO on September 30 that killed two soldiers in northwestern Pakistan.