The Pakistani Taliban had threatened attacks on NATO convoys travelling to Afghanistan when Pakistan ended a seven-month blockade of supply lines last month.
The routes were reopened after the US apologised for a NATO air strike that killed 24 Pakistani soldiers last November. This was the second attack on NATO vehicles in Khyber Agency, one of the main supply routes to Afghanistan, in nearly two weeks.
A NATO truck driver was killed and his aide was injured when Taliban militants attacked the vehicle in Khyber Agency on July 24.
On Sunday, two NATO trucks were torched by suspected militants in the southwestern province of Balochistan. There were no casualties in the attack.
The Taliban had claimed responsibility for the attack in Khyber Agency last month. Tehrik-e-Taliban Pakistan spokesman Ehsanullah Ehsan had then said that the militants would attack NATO trucks in future.
Authorities had temporarily suspended NATO supplies after the attack on July 24.
On Saturday, the northwestern supply route was opened after a two-week suspension. The attacks have again raised concern about the security of NATO supply vehicles.
NATO contractors had demanded security of their vehicles when Pakistan reopened the supply lines last month. The federal government has said that provincial authorities are responsible for the security of NATO vehicles.
Hardline religious groups like the Jamaat-ud-Dawa have opposed the reopening of NATO supply lines and organised protests across Pakistan.
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