At least 45 people have been killed in a suicide bombing in a Pakistani tribal village on the border with Afghanistan, officials said.
At least 90 people were wounded in the explosion in Yakaghund village in the Mohmand tribal region.
The bomber came on a motorbike and blew himself up near the gate of the local administrator's office, witnesses said.
Mohmand is part of Pakistan's lawless tribal belt where Taliban and al-Qaeda are believed to be strong.
The explosion hit a commercial area, destroying vehicles and shops and burying a number of people under the rubble.
The blast damaged the wall of a nearby prison, allowing some prisoners to escape.
Witnesses said a large number of people were waiting outside the administrator's office when the explosion took place.
"It appeared as though the bike lost its balance and was about to fall, and just then there was a huge explosion," a soldier who was on duty at the office said.
Security forces have cordoned off the area and rescue teams are working at the site of the blast.
More than 40 seriously wounded people have been taken to hospitals in Peshawar city while more lightly injured people were treated in a local hospital.
Witnesses said the dead and injured included women and children.
'Militancy spillover'
The Mohmand tribal region borders Afghanistan's Kunar province. To the north, it borders Pakistan's Bajaur tribal region.
Over the last three years, Mohmand has witnessed a spillover of militancy from Bajaur.
Local militant groups have emerged to challenge Pakistani authority in the region, the BBC's M Ilyas Khan in Islamabad says.
The military has been largely able to restore its control over all the main towns and countryside in Mohmand and in September last year the commander of local forces in Mohmand said 80% of the area had been cleared of militants.
But the military have apparently not been able to crush them conclusively, our correspondent adds.
There have been frequent militant attacks on security check-points and military convoys in the area since then.
Last month, militants launched a major assault on a border post in Mohmand, forcing many soldiers to flee into Afghanistan.
Most of them were later handed over by Afghan authorities to Pakistan but nearly a dozen soldiers are still missing, believed to have been captured by the Taliban.
In subsequent weeks, military jets have carried out bombings of suspected militant hideouts in the region.
