Updated

A police official in Pakistan says a bomb blast targeting refugees registering with the government has killed four people in northwestern city of Peshawar.

Faisal Mukhtar says the bombing Sunday on a soccer field also wounded eight people. He says it happened as officials registered refugees from the nearby Khyber tribal region.

Government official Manzoor Khan says the assault appears to be a suicide attack. Mukhtar says police are investigating.

No one immediately claimed responsibility for the attack.

Peshawar sits next to Pakistan's tribal region, which is home to a mix of local Pakistani and al-Qaida-linked foreign militants.

Pakistan's local Taliban have been fighting against the state in a bid to overthrow the government and install their own harsh brand of Islamic Shariah. They've killed thousands of people.