A suicide bomber blew himself up after walking into a mosque within a pro-Taliban seminary in northwestern Pakistan on Friday, killing a top cleric and five other worshippers and wounding dozens of others ahead of the fasting month of Ramadan, according to local police.

The blast occurred in Akora Khattak, a district in Khyber Pakhtunkhwa province, said district police chief Abdul Rashid. He named Hamidul Haq, who is the head of a faction of the Jamiat-e-Ulema Islam (JUI) party, as being among the dead. No group has immediately claimed responsibility, AP reported.

Haq is the son of Maulana Samiul Haq, known as the “father of the Taliban,” who was killed in a knife attack at his home in 2018.

Haq’s family confirmed he was killed in Friday's attack and appealed to his followers to remain peaceful. He was also in charge of the Jamia Haqqania seminary, where many Afghan Taliban had studied in the past two decades.

Zulfiqar Hameed, the provincial police chief, said more than a dozen police officers were guarding the mosque when the attack occurred, and Haq’s seminary also had its own security.

Pakistan's Prime Minister Shehbaz Sharif condemned the attack, which 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 crescent moon.

Yawar Zia, a police officer who was wounded in the attack, said he was on a security duty at the seminary when the attack occurred and splinters from the bomb hit him. He was transported to the Qazi Hussain Ahmed Hospital by ambulance.

“After offering prayer, Hamidul Haq was leaving the mosque to go home and as he reached the main gate, a powerful explosion occurred, and I fell to the ground, losing consciousness,” Zia said from his hospital bed.