The incident happened in a village in the Lakki Marwat district of the province, as the victims, members of the same family entered their farmland where an explosive device was buried, Xinhua reported citing the police.
The injured people were shifted to a nearby hospital.
No group or individual claimed responsibility for the attack.
The area was cordoned off for investigations, police said, adding that the incident seemed to be an outcome of personal enmity, but the possibility of a terrorist attack can not be ruled out.
AMK/PR
