Security agencies have identified the suicide bomber involved in the deadly attack at a mosque in Islamabad’s Tarlai area and secured key evidence, including CCTV footage of the incident, government sources said on Friday.

The bombing during Friday prayers killed at least 31 worshippers and injured more than 169 others. Dozens of the wounded were shifted to the Pakistan Institute of Medical Sciences (PIMS), where several remain in critical condition, officials said.

According to government sources, the attacker had received terrorist training in Afghanistan and had travelled to the country several times. He had returned to Pakistan some time before carrying out the attack.

Investigators have obtained closed-circuit television footage from inside and around the imambargah, which recorded the moment of the explosion at 1:38 p.m.

Officials said the footage shows the route leading to the mosque, the attacker running into the premises moments before the blast, and scenes of panic as worshippers fled after hearing the explosion. The recording also captures the stampede-like situation that developed immediately after the attack.

Sources said militant groups operating under the Taliban regime in Afghanistan pose a threat to regional security. They alleged that terrorist attacks in Pakistan are carried out with support from networks based in Afghanistan in collusion with India.

They said such “cowardly attacks” would not weaken the resolve of the Pakistani nation, which remains united against terrorism.

Police earlier said the attacker was affiliated with the banned militant group Fitna al-Khwarij. Investigators said he attempted to enter the mosque during prayers but was stopped by worshippers and security personnel at the entrance gate, after which he detonated the explosive device.

Eyewitnesses said gunfire was heard shortly after the first unit of prayer, followed by a powerful explosion when worshippers were in prostration.

Following the blast, police, rescue teams, law enforcement agencies and bomb disposal squads rushed to the scene. The area was sealed off, nearby roads were closed, and security was tightened across the federal capital on the instructions of the Islamabad inspector general.

Initial rescue efforts were carried out by residents, who shifted the injured to hospitals before ambulances arrived. A forensic team collected body parts and other evidence from the site to support the investigation.

Interior Minister Mohsin Naqvi directed Minister of State Talal Chaudhry to visit PIMS, where he met the injured and instructed hospital authorities to provide special medical facilities. Sources said relatives of senior police officials were also among those affected.

Prime Minister Shehbaz Sharif strongly condemned the attack, expressed deep sorrow over the loss of lives, and offered condolences to the bereaved families. He later met Interior Minister Naqvi to review the security situation and ordered a full and transparent investigation to identify and arrest those responsible.

President Asif Ali Zardari also condemned the bombing, calling the targeting of innocent worshippers a crime against humanity, and directed authorities to ensure all possible medical assistance for the injured.

Foreign diplomats, including the British and Iranian envoys, also denounced the attack and expressed solidarity with Pakistan.