The blasts went off when officials were distributing food in the camp in Kohat, said officer Zafar Iqbal.

Pakistan has been hit by near daily explosions over the last 18 months blamed on Al-Qaeda and Taleban militants.

Most have been directed at security or government installations, but civilians have also been targeted.

The camp hit Saturday was for people who had left Orakzai district, where the army has been fighting militants since the end of last year. The tempo of the operations has picked since March, with near daily aerial bombardment.

Police officer Khalid Umarzai said at least 20 people were killed and 30 others wounded in the twin bombings, which happened within 10 minutes of each other.

Earlier, an official said security forces backed by artillery and helicopters had killed at least 25 militants in Orakzai late on Friday.

About 210,000 civilians have fled from Orakzai since the fighting began at the end of last year, including nearly 50,000 people who have left in the last month when ground forces moved into the area to flush out insurgents.