Another five soldiers were wounded in the attack in Bannu district, the military's public relations wing said in a statement.

Pakistan's restive northwest, which borders Afghanistan, has seen a rise in attacks over the last year since talks between Islamist militants and the government broke down.

The military said security forces had cordoned off the area. No group immediately claimed responsibility for the attack.

Another suicide bombing at a political gathering in the northwest last month killed more than 60 people. That attack was claimed by the Islamic State militant group.

(Reporting by Gibran Peshimam; Editing by Andrew Heavens)