At least four died in apparent suicide attack in Peshawar targeting refugees registering with the government.
"Abomb blast targeting refugees registering with the government killed four people in the northwestern city of Peshawar," a police official said, Al-Jazeera reported.
Faisal Mukhtar said the blast on Sunday on a football field also wounded eight people. "The explosion happened as officials registered refugees from the nearby Khyber tribal region," Mukhtar added.
Government official Manzoor Khan said the assault appeared to be a suicide attack, stressing that "police are investigating the attack".
No one immediately claimed responsibility for the blast.
Peshawar sits next to Pakistan's tribal region, which is home to a mix of local Pakistani and Al-Qaeda-linked foreign fighters.
Pakistan's local Taliban have been fighting against the state in a bid to overthrow the government.