Militants armed with rockets and assault rifles have attacked a Nato convoy in north-west Pakistan, torching two oil tankers, officials say.
A driver and his assistant sustained burns as the lorries went up in flames in the Khyber tribal region.
Traffic along the route near the town of Jamrud was suspended.
Taliban militants, and sometimes criminal gangs, occasionally attack trucks on Nato's main supply route to Afghanistan.
Pakistan closed its main north-western border crossing to Nato convoys for nearly two weeks in October after a cross-border Nato helicopter assault killed two Pakistani soldiers.
Scores of Nato supply vehicles were destroyed in gun and arson attacks while the crossing was shut.