NATO said in a statement that the attack happened on Wednesday. No further details were released.

The bombing happened the same day Taliban militants seized 16 Afghan demining experts near the Pakistan border. All but seven of them were released hours after the ambush.

Fazel Wahab, from OMAR, an Afghan humanitarian group working to find and dismantle homemade bombs, said the attack happened near the Torkham border crossing in Nangarhar province.