The Islamic State-Khorasan (IS-K) extremist group has claimed responsibility for a suicide bombing that killed at least 54 people and wounded 100 others at a political rally in northwest Pakistan held by a religious group allied with the government.
IS-K claimed responsibility in a statement on its Telegram channel on July 31.
The Pakistan Taliban, or TTP, said in a statement sent to the AP that the bombing was aimed at setting Islamists against each other.
The attack compounds security concerns in the run-up to a national election later this year.
Elections are to be held before early November following the end of the government's tenure in the first half of August.
Prime Minister Shehbaz Sharif denounced the blast as an attack on the democratic process.
Police said the blast rocked a district convention of the Jamiat Ulema-e Islam Pakistan (JUI) party around 5 p.m. on July 30 in the Bajaur tribal district in Khyber Pakhtunkhwa Province, which borders Afghanistan.
Firebrand cleric Maulana Fazlur Rehman, who heads the JUI, was not at the rally, party officials told AP. But officials reported that Maulana Ziaullah, the local leader of the party, was among the dead.
Officials said the seriously wounded were being airlifted to Peshawar, the provincial capital, where better medical care was available.
Bajaur has long been a sanctuary for Islamist extremists, including the Tehrik-e Taliban Pakistan (TTP), known as the Pakistani Taliban, and the Islamic State (IS) group.
Rehman is considered to be pro-Taliban and his political party is part of the coalition government in Islamabad, but the TPP has previously claimed attacks on JUI party members.
Rehman has on many occasions condemned TTP violence in Pakistan, asserting that its "jihad" in Pakistan is un-Islamic and unconstitutional and has urged the TTP and similar groups to seek power through the electoral process. He did support the Afghan Taliban's war against the now-deposed Western-backed government in Afghanistan.
The TPP later issued a statement condemning the bombing, saying it was intended to pit Islamist groups against each other. The Afghan Taliban also said it condemned the attack.
IS has also previously said it was responsible for attacks against religious scholars affiliated with the JUI, which operates mosques and madrasas in the region.
Pakistan conducted a massive military operation against extremists across the northwestern regions in June 2014, forcing many militants and leadership to take refuge across the border in Afghanistan.
However, the TTP has gradually staged a comeback in the mountainous tribal regions since late 2019 and considerably increased the frequency of their attacks in the past two years.
The TTP is a separate militant group from the Afghan Taliban, which toppled the Western-backed government in Kabul in mid-August. But Pakistan's militant groups are often interlinked with those across the border in Afghanistan and the TTP follows the same hard-line Sunni Islam as its Afghan counterparts.
On July 20, two police officers were killed and at least 10 wounded in Peshawar when two suicide bombers attacked a security and administrative compound in the Bara Tehsil neighborhood.
Protesters across the northwestern province have called on Islamabad to provide security as returning TPP fighters asserted control in the volatile region.