The bomber detonated his suicide vest as about 150 worshipers were praying inside.

At least 20 persons were killed and 96 others injured after a suicide bomber detonated a bomb inside a mosque on Monday, Jan. 30, in the northwestern Pakistani city of Peshawar.

It was gathered that the incident took place as about 150 worshipers were praying inside.

The impact of the explosion collapsed the roof of the mosque, which caved in and injured many, according to Zafar Khan, a local police officer.

No one immediately claimed responsibility for the bombing, said Saddique Khan, a senior police official in Peshawar who gave the latest casualty tolls, but the Pakistani Taliban have been blamed in similar suicide attacks in the past.

A survivor, 38-year-old police officer Meena Gul, said he was inside the mosque when the bomb went off. He said he doesn’t know how he survived unhurt. He could hear cries and screams after the bomb exploded, Gul said.

Worshippers were trapped under the rubble as rescuers tried to remove mounds of debris from the mosque grounds to save them.

Several of the wounded were listed in critical condition at a hospital and there were fears the death toll would rise.

Prime Minister Shahbaz Sharif in a statement condemned the bombing, and ordered authorities to ensure the best possible medical treatment to the victims. He also vowed “stern action” against those who were behind the attack.