A suicide bomber hit a Pakistani security checkpoint yesterday at the main border crossing for convoys ferrying The North Atlantic Treaty Organisation (NATO) supplies into Afghanistan, killing at least 18 border guards, police said.

The attacker approached on foot and detonated his explosives at the Torkham checkpoint in the Khyber region, local police officer Sadiq Khan said.

Border guards were gathering in front of their barracks after sunset for a meal to end their Ramadan fast when the bomber struck, according to Jehanzeb Lateef, spokesman for the federal agency that administers the region.

At least 18 security officials were dead and dozens reported wounded, Lateef said, adding that the death toll could rise. The border had closed for the day a few hours earlier.

Ali Raza, an official in the administration office, said he heard a huge explosion in the building next door.

“We rushed out and saw destruction all around,” Raza said. He helped rush the wounded to a hospital.

Several of the wounded told Raza that the last thing they saw was a young boy approaching with what looked like jugs of water for the security officers, but no one could confirm he was the bomber.

The Torkham checkpoint marks the main border crossing from the Khyber Pass into Afghanistan.

Some 300 supply trucks traverse the passage daily, and U.S. and NATO troops in landlocked Afghanistan rely on the supply line for up to 75 percent of their fuel, food and other logistical goods.