The target of the attack was tribal police in Khar, the main town of Bajaur tribal district.
According to sources, Levies Force were conducting routine checking at Khar Bazaar when a suicide bomber blew himself that killed eight persons initially. Later the toll rose to 22 while 42 others were injured who were shifted to Tehsil Headquarters Hospital.
A senior official confirmed that it was a suicide attack and four tribal policemen were killed including chief of Bajaur Levies Force, Major Javed and Deputy Chief, Subedar Fazal Rabbi. The bomber was on foot and detonated his explosive vest when he reached a police check post, sources added.
Witnesses told the bomber was aged between 14 and 18 years. Security forces cordoned off the area and imposed curfew soon after the blast.
There was no immediate claim of responsibility. The attack came two days after Pakistan went on a high state of alert for the first anniversary of Osama bin Laden’s killing by American troops, fearing a wave of revenge attacks.
Tribal police, who are recruited to help the government fight Taliban militants in the tribal belt, are frequently attacked.
Two bomb attacks killed at least five people – pro-government tribal elders and security personnel – in same district on Thursday.