Distraught relatives thronged hospitals in Pakistan’s Peshawar on Tuesday to look for their kin a day after a suicide bombing ripped through a crowded mosque in a heavily fortified area of the city, killing more than 90 people, mostly policemen.

The attack, in the Police Lines district follows a surge in violence targeting police in this restive, northwestern city near the Afghan border. No group has claimed responsibility.

“My son, my child,” cried an elderly woman walking alongside an ambulance carrying coffins, as rescue workers stretchered wounded people to a hospital emergency unit.

At least 170 people were wounded in the blast, which demolished the upper storey of the mosque as hundreds of worshippers performed noon prayers.

Riaz Mahsud, a senior local government official, said the casualty toll was likely to rise as workers searched through the debris. “We cut three main beams of the building and efforts are underway to cut the remaining one,” he told Reuters. Live video footage showed people scrambling to hospitals to identify the dead and tend to the wounded.

The mosque is the main place of worship in the district, which houses offices for the police and counter-terrorism unit.

Authorities say they do not know how the bomber managed to enter the area, which is protected by a series of checkpoints manned by police and military personnel. Defence minister

Khawaja Asif said the bomber was stood at the first row in the prayer hall when he detonated his explosives. Peshawar sits on the edge of the Pashtun tribal lands, a region mired in violence for the past two decades. The most active militant group in the area is the Pakistani Taliban, also called Tehreek-e-Taliban Pakistan (TTP), an umbrella group for Sunni and sectarian Islamist factions opposed to the government in Islamabad.

The TTP denied responsibility for Monday’s bombing, though it has stepped up attacks since withdrawing from a peace deal with the government last year.

The bombing took place a day before an International Monetary Fund (IMF) mission arrives in Islamabad for talks on a stalled $7 billion bailout.

The latest attack was even more deadly that one claimed by Islamic State militants in March last year, when they bombed a Shia mosque, killing at least 58 people.