At least 22 people have died and dozens more are wounded after a bomb exploded on Saturday at a market in a north-west tribal region of Pakistan that borders Afghanistan.
Shahid Khan, an assistant administrator in the Kurram tribal region, said the explosion took place in regional capital Parachinar when the market was crowded with retailers buying fruits and vegetables from a wholesale shop.
As well as the 22 fatalities, Mr Khan said the number of people wounded stood at more than 50, including those who sustained minor injuries.
Lashker-e-Jhangvi, a banned sectarian militant group that has attacked minority Shiites Muslims in the past, claimed responsibility for the attack.
The bombing took place in a predominantly Shiite area of Kurram, which has seen attack by Sunni militants who have hideouts there. Shiites are a minority in Pakistan.
"That was our combined work with Shahryar group of Mahsud Taliban," Ali Sufyan, a spokesman for the banned group, wrote in a text message to an AP reporter.
Kurram has been the scene of increased militant activities in recent years and the army carried out a massive operation against extremists in the region, but they still have the capacity to strike.
As well as being taken to hospital in Parachinar, some of the injured were airlifted to hospitals in Peshawar, the capital of north-western Khyber Pakhtunkhwa province.
Hospitals in tribal regions and rural areas of Pakistan typically are not equipped to handle such emergencies.
Iqbal Zafar Jhagra, the provincial governor, told local Geo television the remnants of militant groups targeted by security forces were trying to show their existence by such attacks.
"Terrorists largely eliminated by our security forces and the remaining will soon meet their fate if we all together rise against them," he said.