A car bomb ripped through a market area in Khyber Agency near the Afghan border on Saturday, killing 25 people including three children, officials said.
Hospital officials confirmed the toll.
Zeb said there were 18 bodies at the Landi Kotal hospital while seven victims had died while being taken for treatment in Peshawar. The dead included three children aged nine, 10 and 12, he added.
Motor mechanic Sajidullah Khan, who was wounded in the leg, forearms and face, told AFP: "I was checking a car when I heard a huge blast nearby. I knew nothing afterwards and came to in the hospital."
Shakoor Jan, an electrician, said he was sitting in his shop when the blast rocked the whole area. "There was fire in several shops," he said. No group has claimed responsibility for the blast yet. Arshad Khan, a local administration official, said the blast appeared to be aimed at members of the pro-government Zakha Khel tribe, who oppose a local warlord, Mangal Bagh.
Bagh's Lashkar-i-Islam group has links to militants and criminal gangs.
"The bomb was planted in a pick-up truck parked near the bus stand," Khan said.
Six shops were gutted and several damaged in the blast, which also destroyed at least eight vehicles, he added.
It should be mentioned here that the blast site is a central commercial hub of Landi kotal and was heavily crowded at the time of explosion.
Prime Minister Syed Yousuf Raza Gilani has strongly condemned the blast in Landi Kotal Bazar, Khyber Agency resulting in loss of innocent lives and injuring many.
The Prime Minister has reiterated the resolve of the government to fight against terrorism and bring the terrorist elements to justice. He asked the political administration of Khyber Agency to provide best medical facilities to the injured.