At least 88 people have been killed after a suspected suicide bomb attack at a volleyball match. Local police have said 42 people were wounded.
It is understood some people were trapped under rubble after a house collapsed.
There are conflicting reports on how the attack happened and police say they are still conducting an investigation.
The bomber struck as young men in a village near the town of Lakki Marwat were playing volleyball in front of a crowd of spectators, including elderly residents and children.
Al Qaeda-linked Taliban militants are known to have strongholds in the region.
An attack on a sporting event is highly unusual, although militants have recently started bombing crowded civilians areas like markets to inflict mass casualties, spreading fear and chaos.
Eye witnesses say they saw the bomber drive a vehicle onto the playing field and blow himself up.
The bombing has occurred on a day of protests against violence in Pakistan.
Pakistan's commercial capital Karachi nearly shut down as religious and political leaders called for a strike to denounce bloodshed after a suicide bomber killed 43 people at a religious procession this week.
On a visit to Karachi on Friday, Interior Minister Rehman Malik said militant groups were harming Pakistan.
‘They are hired assassins. They are enemies of Pakistan. They are enemies of Islam,’ he told reporters.
While many Pakistanis object to the violence, they are also frustrated with the government's inability to stabilise the nuclear power.
Militants have become increasingly brazen in their bid to topple the government and impose their brand of Islam, including public floggings and executions for anyone who disobeys them.
The Karachi carnage illustrated their reach is growing, from bastions on the Afghan border to cities, including an attack on a mosque near the headquarters of the powerful military.
Karachi's streets were nearly empty today. The stock exchange, which normally operates on the first day of the year, was closed.