Four people have been arrested on suspicion of facilitating a suicide bombing that killed more than 30 people on Friday, Pakistan's interior minister has said.

Mohsin Naqvi stated that an Afghan national alleged to be the mastermind behind the attack was among those detained. Tragically, one counter-terrorism officer was killed and three others were wounded during the raids aimed at arresting the suspects.

The Islamic State group has claimed responsibility for the bombing, which targeted Friday prayers at the Shia mosque in the Tarlai area, where worshippers had gathered in large numbers.

More than 160 individuals were injured in the blast, marking it as the deadliest attack in Islamabad in over a decade. Huge crowds were seen in the city as thousands mourned the victims, with funeral prayers held under tight security.

Pakistan's Prime Minister Shehbaz Sharif expressed 'deep grief' over the incident, while President Asif Ali Zardari condemned the attack, labeling it a crime against humanity.

Naqvi accused India of funding the attack and providing targets, leading to rejection of these claims by the Indian foreign ministry as 'baseless.' Pakistani Defence Minister Khawaja Asif also suggested Afghan involvement in the incident, prompting a strong rebuttal from the Afghan Taliban government.

In response to the attack, Naqvi has pledged to enhance security in Islamabad by recruiting thousands of new police officers and upgrading the city’s security systems.

While attacks in the capital are usually rare, they have been escalated by a recent wave of violence in the region, including coordinated attacks in Balochistan that left numerous civilians dead.