At least 17 people were killed in a suicide attack on a market in the northwestern Pakistan of Kohat on Wednesday, a senior police official said.
The explosion took place at a busy bus terminal in the garrison town's main Tirah bazaar, Kohat police chief Dilawar Bangash told AFP.
"It was a suicide blast. The death toll has risen to 17," he said, adding that 25 others were wounded, seven of them seriously.
It is the latest bombing in a long series of attacks in Pakistan blamed on networks linked to the Taliban and Al Qaeda.
Local police spokesman Fazal Naeem said the bomber approached the door of a bus carrying passengers to the nearby tribal district of Orakzai and detonated his explosives.
Television footage showed two damaged passenger vans parked at the terminal. A woman was crying while people tried to console her. Earlier it appeared the bomb was planted in a vehicle parked at the main bus stand, but Bangash said that "now we have found the head and legs of the suicide bomber".
Bangash said it was not immediately clear who was the target. The victims were both Sunni and Shiite Muslims, he said.
The blast, the third in as many days, is part of a new wave of bombing after a brief lull.
A double suicide bombing in the tribal district of Mohmand near the Afghan border killed 43 people on Monday.
Police said two suicide bombers dressed in police uniform attacked a meeting of anti-Taliban militiamen and pro-government elders in Ghalanai, about 175 kilometres northwest of Islamabad.
A purported spokesman for the Pakistani Taliban claimed responsibility for that attack, threatening death to anyone who forms militias against the Islamists.
On Tuesday a suicide bomber tried to kill the chief minister of Pakistan's southwestern province of Baluchistan, damaging his motorcade but leaving the minister unhurt, officials said.
The blast wounded nine people near the convoy of Nawab Aslam Raisani in Quetta, the capital of a province where separatist, sectarian and Taliban violence has surged this year.
A purported spokesman for the banned extremist group Lashkar-e-Jhangvi claimed responsibility, saying Raisani had been targeted for efforts to provide security to Shiite Muslims, who are frequently attacked in Baluchistan.
Around 4,000 people have died in suicide and bomb attacks across Pakistan since government forces raided an extremist mosque in Islamabad in 2007. The attacks have been blamed on networks linked to the Taliban and Al Qaeda.