A remote-controlled bomb blast killed 35 people and wounded more than 60 others on Tuesday in the deadliest attack in months in the Taliban-hit tribal region of northwest Pakistan.
The explosion took place in a market in Jamrud, one of the towns of the troubled Khyber tribal region, which also used to serve as the main supply route for Nato forces operating in Afghanistan.
"The total number of deaths in the blast is 35 while 69 people were wounded, and of them the condition of 11 is critical," a senior administration official, Shakeel Khan Umarzai, told AFP.
Another top official in Khyber, Mutahir Zeb, said the target of the attack was not immediately clear.
"According to initial information, it was a remote controlled device planted in a passenger pickup van," he said.
Pakistan's remote and lawless northwestern region is a stronghold of Taliban and Al-Qaeda operatives and other Islamist militants opposed to the government.
Insurgents largely based in the tribal border lands have carried out bomb and gun attacks killing more than 4,700 people across Pakistan since July 2007.
But the market attack was the first major Islamist militant attack in Pakistan since a suicide bomber killed 46 people, targeting anti-Taliban militia at a funeral in the northwestern district of Lower Dir on September 15.
Pakistan has battled a homegrown insurgency for years, with more than 3,000 soldiers killed in the battle against militancy.
On Monday Pakistani authorities recovered the bodies of 10 soldiers in an exchange of bodies with Taliban militants following a clash two weeks ago in the tribal belt.
An official with the military's media wing said the soldiers had been missing in Orakzai district since December 21 when rebels attacked a checkpost and killed 13 others.
That exchange came four days after the corpses of 15 members of Pakistan's paramilitary Frontier Constabulary were found in the northwestern town of Shawa, in North Waziristan tribal region near the Afghan border, almost two weeks after they were kidnapped.
There were about 120 bomb attacks in Pakistan in 2011 and the same number in 2010 according to an AFP tally, an increase from 2009, but far below the violence of 2009 when there were more than 200 bomb blasts.
The latest attack comes as the northwest border crossing for NATO supplies remains closed to trucks bound for foreign troops fighting in neighbouring Afghanistan following a crash in US-Pakistan relations in the wake of deadly NATO airstrikes on November 26 that killed 24 Pakistani soldiers.
Pakistan rejected the results of the military coalition's investigation into the incident and said the strikes had been a deliberate act of aggression, leaving relations floundering between the uneasy anti-terror allies.