The explosion occurred as worshippers had collected in the Kucha Risaldar mosque in Peshawar’s old city for Friday prayers, police said.
Peshawar police Chief Muhammed Ejaz Khan said the violence started when two armed attackers opened fire on police outside the mosque.
One attacker and one policeman were killed in the gunfight, and another policeman was wounded. The remaining attacker then went inside the mosque and detonated a bomb.
Ambulances rushed through congested narrow streets carrying the wounded to Lady Reading Hospital, where doctors worked feverishly. No one immediately claimed responsibility.
More than 60 people were injured and the death toll may rise, said hospital spokesman Mohamed Asim.
“We are in a state of emergency and the injured are being shifted to the hospital. We are investigating the nature of the blast but it seemed to a suicide attack,” police officer Mohammad Sajjad Khan said.
Similar attacks have occurred in the region, located near the border with neighboring Afghanistan.
Shayan Haider, a witness, had been preparing to enter the mosque when the powerful explosion threw him to the street.
“I opened my eyes and there was dust and bodies everywhere,” he said.
At the Lady Reading Hospital Emergency department, there was chaos as doctors struggled to move the many wounded into operating theatres.
Prime Minister Imran Khan condemned the bombing.
In recent months Pakistan has experienced an increase of violence. Dozens of military personnel have been killed in scores of attacks on army outposts along the border with Afghanistan.
Source: Al Jazeera