A powerful bomb exploded at a mosque within a pro-Taliban seminary in northwestern Pakistan on Friday, killing at least five worshippers and wounding dozens of others ahead of the fasting month of Ramadan, according to local police.

The blast occurred in Akkora Khattak, a district in Khyber Pakhtunkhwa province, Abdul Rashid, a district police chief said.

He said officers are investigating, and the dead and wounded are being transported to hospitals.

No group has immediately claimed responsibility for the attack inside Jamia Haqqania, a seminary which is known for links with the Afghan Taliban.

The bombing came ahead of the Muslim holy month of Ramadan, which is expected to start either on Saturday or Sunday subject to the sighting of the moon.