Islamabad, Pakistan (CNN) -- A young, female suicide bomber was behind a blast in Pakistan that killed at least 46 people and injured 105 others at a food distribution point, an official said Sunday. 

Zakir Hussain Afridi, the top government official in Bajaur Agency, Pakistan, said that the preliminary investigation into the explosion shows that a girl between the ages of 16 and 18 blew herself up. The determination was made from remains of the bomber that were recovered. 

The Pakistani Taliban claimed responsibility for Saturday's blast in that Asian nation's tribal region. 

Azam Tariq, the central spokesman for the Pakistani Taliban, told CNN in a phone call that it targeted people who had formed what he called a pro-government and anti-Taliban group. 

The blast took place about 600 meters from a U.N. World Food Programme distribution point at a security checkpoint in Khar, according to Amjad Jamal, a spokesman for the agency. He said that more than 300 people were going through a security screening to get food and other items at the time of the explosion. 

Khar is the headquarters of Bajaur Agency, one of the seven districts of Pakistan's tribal region bordering Afghanistan. Jamal said that those who had been internally displaced during military efforts in Bajaur Agency get a month's supply of food and other goods. 

Afridi said that the suicide bomber was in a burqa, a traditional full-body covering worn by some Muslim women. He said she was stopped for a security check at a checkpoint, where she detonated herself. 
What happened there?
she detonated herself.