The official said at least 20 people had been wounded in the blast in the market in the Khyber region, near the border with Afghanistan, and the death toll could rise.

The attack occurred near the office of a senior government official but it was unclear if he was the target of the attack, the news channels reported.

There was no immediate claim of responsibility.

The security official said it was not clear if the blast had been caused by a suicide attacker or a planted bomb.