A female suicide bomber killed at least 43 people waiting for food at an aid distribution centre in Pakistan on Saturday.
The blast took place in the town of Khar in the Bajaur region, a tribal area close to the Afghan border - a Taliban and al-Qaeda stronghold.
Reports say at least another 100 people were wounded and there are fears the death toll could rise.
The Taliban said it was responsible for the attack.
It's believed that for the first time in Pakistan, the suicide bomber was a woman.
The BBC reports those in the crowd were members of the Salarzai tribe, which has supported the army's operations against the Taliban.
An estimated 300 people were queuing for food at the time of the blast.
Dozens of injured people were taken to hospital by military helicopter.
The bomber was dressed in a full-length burka.
The district of Bajaur has seen several military operations to clear it of insurgents.
The army previously declared the operations a success and said the area safe for displaced people to return to.