Officials have vowed to hunt down and arrest the masterminds behind a deadly mosque attack in Pakistan claimed by an affiliate of the so-called Islamic State (IS).

The assault killed 63 people and wounded nearly 200 at Kucha Risaldar mosque in north-west Peshawar.

IS said the lone suicide bomber was from neighbouring Afghanistan.

He shot two police guarding the Shia Muslim mosque before exploding his device inside the building, according to a statement from the militants. The attack took place as worshipers knelt in Friday prayer.

The IS affiliate, known as IS in Khorasan Province, is headquartered in eastern Afghanistan.

The Taliban rulers in Afghanistan, who have been fighting IS, condemned the attack.

IS has proven to be the Taliban’s greatest security threat since sweeping into power last August.

Taliban deputy minister for culture and information Zabihullah Mujahid tweeted: “We condemn the bombing of a mosque in Peshawar, Pakistan. There is no justification for attacking civilians and worshipers.”

He refused to comment on the IS claim that the suicide bomber was Afghan.

Pakistanis are burying their dead amid heavy security. Police carried out body searches of mourners who were then searched a second time by security provided by Pakistan’s Shia community.

Hundreds of mourners attended funeral prayers for 13 victims late on Friday and for another 11 on Saturday at Peshawar’s Kahoti Gate.

One of the police officers who was shot outside Kucha Risaldar mosque died immediately and the second died later from his wounds, police officials said.

Pakistan’s information minister Fawad Chaudhry said three investigation teams were established to study forensic evidence and closed-circuit TV footage to track down the attack’s organisers.

In CCTV footage seen by The Associated Press, the lone attacker concealed his bomb beneath a large black shawl.

The footage showed the bomber moving quickly up a narrow street toward the mosque entrance. He fired at the police protecting the mosque before entering inside.

Within seconds, there is a powerful explosion and the camera lens is obscured with dust and debris.

The crudely made device was packed with ball bearings, a deadly method of constructing a bomb to inflict maximum carnage because it sprays deadly projectiles over a large area. The ball bearings caused the high death toll, police said.

Immediately after the bombing, Pakistan’s minority Shias slammed the government for lax security arrangements, demanding greater attention to their safety.

Friday’s attack in Peshawar’s congested old city was the worst in years in Pakistan. The country has seen renewed militant attacks after several years of relative quiet that followed military operations against militant hideouts in the border regions with Afghanistan.

The attacks have mostly been carried out by the Pakistani Taliban since last August when the Afghan Taliban swept into power and America ended its 20-year involvement in Afghanistan.

The Pakistan Taliban are not connected to the new Afghan rulers. However, they are hiding out in Afghanistan and despite Pakistan’s repeated request to hand them over, none have yet been found and expelled.

The Islamic State affiliate, often referred to as IS-K, is an enemy of the Afghan Taliban and has carried out successive operations against them since coming into power last year. Pakistani security officials have insisted IS has little presence in Pakistan, yet in their statement claiming responsibility for the mosque attack, IS vowed to carry out more attacks in both Pakistan and Afghanistan.