A rescue worker searching for survivors in the deadly blast carried out by ISIS terrorists

Washington: The United States condemn in the strongest terms the attack in north-western Pakistan on Sunday during a political rally, States Department official spokesperson Matthew Miller said on Tuesday (local time).

He added that the Pakistani people have suffered greatly at the hands of terrorists through this deadly attack that killed 54 people and left nearly 200 wounded.

"We condemn in the strongest terms the attack in northwestern Pakistan on Sunday during a political rally. We are deeply saddened by the loss of life and injuries sustained from the explosion and share our heartfelt condolences with those affected by the attack. The Pakistani people have suffered greatly at the hands of terrorists," Miller said while addressing a regular States Department press briefing on Tuesday.

The Islamic State group on Monday claimed responsibility for the Bajaur suicide blast in Pakistan. The bombing targeted an election rally in Pakistan's border district of Bajaur on Sunday in which 54 people lost lives, including 23 children.

“A suicide attacker from the Islamic State [ISIL] … detonated his explosive jacket in the middle of a crowd” in the town of Khar, the armed group’s news arm Amaq said in a statement, according to Al Jazeera.

A bomber detonated an explosives-packed vest near the platform as some 400 members of the Jamiat Ulema-e-Islam (JUI-F) party, a significant government coalition partner led by hardline politician Fazlur Rehman, awaited the start of the speeches.

The gathering was hosted near a market beneath a huge tent, but Rehman chose not to go. Rehman has previously escaped at least two explosions that occurred at political rallies in 2011 and 2014, Al Jazeera reported.

Police took testimony from some of the injured on Monday at a hospital in Khar, the biggest town in Bajaur. The provincial minister of information, Feroz Jamal, stated that police were "investigating this attack in all aspects."

A First Information Report on the blast was filed with the Counter Terrorism Department on Monday as the initial investigation, according to the police, indicated that the terrorist group ISIS was responsible for the suicide attack.

Maulana Fazlur Rehman, the head of the JUI-F, asked that Shehbaz Sharif, the prime minister, and Azam Khan, the interim chief minister of KP, look into the incident, Geo News reported.

Since last year, when a truce between Tehreek-e-Taliban Pakistan (TTP) and Islamabad collapsed, attacks by extremists have increased in Pakistan. Although cross-border militancy persists, Pakistan has long held Afghanistan responsible for failing to uphold its promise to ensure that its soil was not utilised for terrorism in Islamabad.