At least 40 people were killed and over 130 injured when a suicide bomber set off explosives at a political rally in Pakistan's northwestern Khyber Pakhtunkhwa province on Sunday, police said.
The blast took place at a gathering of the conservative Jamiat Ulema Islam-Fazl (JUI-F) party, known for its links to hardline political Islam, in the former tribal area of Bajaur, which borders Afghanistan.
The provincial police chief Akhtar Hayat told Reuters the explosion was caused by a suicide bomb.
An emergency has been declared in the hospitals of Bajaur and adjoining areas where most of the injured were taken, said district police officer Nazir Khan. The critically injured were transported from Bajaur to hospitals in the provincial capital Peshawar by military helicopters.
"The JUI-F organized a workers convention in Khar town of Bajaur in which 40 people lost their lives and more than 130 were injured," Khan said.
Resurgence of attacks
Pakistan has seen a resurgence of attacks by Islamist militants since last year when a ceasefire between the Tehreek-e-Taliban Pakistan (TTP) and Islamabad broke down.
However, most of the recent attacks have been on security forces and installations, rather than political gatherings.
The TTP pledges allegiance to but is not directly a part of, the Taliban in western neighbor Afghanistan. Pakistan's security forces say the TTP has sanctuaries in Afghanistan, which the Taliban run-administration there denies.
Afghanistan's administration condemned the explosion in a statement by their spokesman Zabihullah Mujahid.
The TTP is not the only militant group to carry out attacks in the area, which has also been hit by a local chapter of the Islamic State.
The targeted party, the JUI-F, is a major ally of the coalition government of Prime Minister Shehbaz Sharif, which is preparing for national elections to be held in November.