The target of the attack is unclear, though insurgents have exploded bombs in public places before.
On Monday, 50 people were killed in two blasts at a government compound in Mohmand, also in the border area.
Suicide bomber kills 15 in northwest Pakistan
PESHAWAR, Pakistan
The blast happened in Kohat city, near Pakistan's border regions
with Afghanistan, where Islamist militants are strong. A spokesman
for the Pakistan Taliban, the main militant group in the northwest,
is claiming responsibility.
