Security officials said the device was planted on a road in Khar Qamar, an area where security forces had recently conducted a search operation following a previous roadside bomb attack.
The Pakistani Taliban, which is separate from the Afghan Taliban, claimed responsibility for the attack, according to Mohammad Khurasani, a spokesman for the movement, many of whose members are based across the border in Afghanistan.
Pakistani forces have conducted a series of operations against militant groups including the Pakistani Taliban in North Waziristan over recent years, although officials now say the area has largely been pacified.
Problems have continued, however, and security officials said at least 10 soldiers have been killed and 35 wounded over the past month in the Khar Qamar area, which has also seen growing tensions with local ethnic Pashtun activists from the Pashtun Tahafuz Movement (PTM).
More about: Pakistan