At least 50 people have been killed in a suicide bombing in a Pakistani tribal village on the border with Afghanistan, officials said.
At least 100 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 tribal regions where the Taliban and al-Qaeda have a strong presence.
A Taliban spokesman, Ikramullah Mohmand, said the rebels claimed responsibility for the attack.
Their target was a meeting of local officials and anti-Taliban elders from the Anbar Utmankhel tribe, he said.
The top government administrator of Mohmand region, Amjad Ali, said the attack signified "increasing desperation" on part of the Taliban, whose "space is being restricted by security forces".
The explosion hit a commercial area, destroying vehicles and shops and burying a number of people under the rubble.
It also damaged the wall of a nearby prison, allowing some prisoners to escape.
Women and children
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.
The Mohmand tribal region borders Afghanistan's Kunar province, while to the north is the Bajaur tribal region of Pakistan Both regions are staging grounds for the Taliban.
The military said in the last year that it has been largely able to restore its control over all the main towns and countryside in Mohmand.
In September 2009 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, a BBC correspondent says.
There have been frequent militant attacks on security check-points and military convoys in the area since September.
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.