ISLAMABAD, Pakistan (CNN) -- At least 21 people were killed and 27 wounded in a suicide bombing Thursday in Pakistan, near its border with Afghanistan, officials told CNN.
The victims were security personnel gathering for a meal to end the daily fast during the Muslim month of Ramadan, a local official told CNN. The official declined to be named.
The suicide bomber entered the barracks of a para-military force in the town of Torkham, in the Khyber agency, or district, and blew himself up, the official said.
Survivors of the attack said the bomber was a young man between 15 and 20 years old who was bringing water to the security personnel, according to Nasir Khan, a local official. He placed jugs of water on the ground and then detonated explosives strapped to his body, Khan said.
A NATO oil tank truck delivering supplies to NATO troops in Afghanistan was blown up a day earlier on the same road in Torkham where Thursday's attack took place.
CNN's Samson Desta contributed to this report.