Authorities in northwest Pakistan say gunmen have opened fire on a truck carrying NATO supplies, killing the driver.

Monday's attack was the second in the Jamrud area of the Khyber tribal region since Pakistan re-opened its two border crossings into Afghanistan last month. The Pakistani Taliban vowed to attack NATO supply convoys when the border reopened.

After the first such incident on July 24, Pakistani officials temporarily closed the Torkham crossing, citing security concerns. It was reopened on August 4.

There was no immediate claim of responsibility for Monday's attack.

Pakistan shut down NATO supply lines into Afghanistan following U.S.-led NATO airstrikes that mistakenly killed 24 Pakistani soldiers near the Afghan border last November.