The explosion occurred just hours after militants blew up the election offices of an independent candidate in the North Wazirstan tribal district fuelling concerns that violence will mar general elections on May 11.
"At least nine passengers have been killed and seven injured. Bomb disposal officials told me that it was a timed device," Fazal Wahid, a senior police official told AFP.
Another officer, Imran Shahid said police were investigating the possibility a suicide bomber was involved in the attack which occurred as the was van passing through the Matani suburb.
The Taliban, who have frequently attacked targets in the area denied they had conducted the attack, claiming they do not target innocents.
An intelligence official in the city said the attack may be a reaction to a fresh military push in the Tirah valley of the Khyber tribal district, where the army has been fighting Taliban and Lashkar-e-Islam militants.
Military officials said heavy fighting between Pakistani troops and militants has killed 23 soldiers and 110 militants in Khyber this week.
Abdul Haq, a senior bomb disposal expert told AFP that four to five kilograms of highly explosive material was used.
The bomb destroyed three shops and a motorcycle, police and witnesses said.
"I was going to buy some milk when a huge blast took place. It was so powerful that it threw me back in my shop," Asad Khan, an 18-year-old shopkeeper in the market told AFP from his hospital bed.
Khan sustained injuries in his right shoulder and legs.
Anwar Ali, a passenger in the bus said the blast overturned the vehicle.
"I was sitting in the front seat when a powerful wave struck me and my head hit the front wind screen. I don't know what happened after that," Ali told AFP.
In an earlier incident, militants blew up the election office of Kamran Khan, a former legislator from North Waziristan who supported the outgoing government led by the Pakistan People's Party. No one was hurt.
COMMENTS (7)
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We would hit every enemy of Pakistan with full force. But Taliban are not our enemy they have only killed less than one lakh of Pakistanis. We are not angry at them yet.
It is shameful that bomb blasts take place in Pakistan is such regular frequency that it has become the norm and no one is shocked by it in international media. Sad state of affairs - feel sorry for the innocent folks who want to go about their lives doing honest work but fear for their lives and well being.
Innocent people died,Taliban's Islam served again.
Its in peshawar, no worries.. until and unless the rest of the country is safe. Welcome to the senselessness of Pakistanis
Taliban are curse for Humanity
Pakistani army needs to conduct wide spread operations all over KP. We cannot live like this fearful of our lives and our family.
was it due to good taliban or bad taliban