The incident encapsulates many of the challenges for NATO tankers and supply lines, including militant attacks, disastrous floods, and mercurial Pakistan-US relations.
The trucks had halted overnight in the town of Shikarpur en route to the only border crossing into Afghanistan that remains open following Pakistan's closure of the Khyber Pass to NATO suppliers Thursday morning. Trucks had only recently started to pass through Shikarpur when a road was reopened that had been washed out by floods this summer.
The incident encapsulates many of the challenges for the NATO supply lines, including militant attacks, disastrous floods, and mercurial Pakistan-US relations. While the level of disruption at the moment remains manageable, further problems could spell trouble.
"If these attacks become frequent and they begin to take a heavy toll on the supply lines then I think it could be a huge source of worry to NATO forces. As the Americans increase their numbers they become ever more dependent on this stable route through Pakistan," says Rifaat Hussein, a strategic analyst at Quaid-i-Azam University in Islamabad.
Pakistan closed the Khyber Pass border crossing following several recent border incursions by NATO forces. The latest incident on Thursday morning involved US helicopters destroying a Pakistani border post, killing three paramilitary troops with the Frontier Corps. Pakistan claims its forces fired warning shots over the incursion.