According to newspaper reports, a suicide bomber killed up to 50 people and wounded dozens in an attack outside the office of a senior government official in Pakistan's northwest, government and hospital officials said.
The bomber struck when people were gathered around the office in the Mohmand Pashtun tribal region near the Afghan border, where security forces have stepped up attacks on Taliban militants in recent weeks.
"There were two blasts. The first one was small but the second was a big one. Up to 46 people have been killed," Rasool Khan, the region's assistant political agent, told Reuters. The attack took place outside his office.
An administration official, Mehraj Khan, had earlier described the incident as a suicide attack.
Hospital officials said nearly 80 people were being treated for multiple wounds, while government officials put the number of wounded at about 40.
Among the wounded were several internally displaced people, who were collecting relief goods near the blast site.
The blast also damaged several cars and about 30 shops, witnesses
"It was a huge blast that flattened dozens of nearby shops and people are still trapped under the rubble," a resident, identified as Ahmed, told the private Express News TV channel.
Television footage showed victims being pulled out of the debris.
A security official at the scene said that blast also damaged a wall of a nearby prison and at least 20 inmates had escaped.
The office was targeted when some 100 people had gathered there to seek redress for their problems.
The Bajaur-Peshawar road was also closed for traffic as rescue
The Pakistani army has carried out operations against Taliban fighters in Mohmand in recent years