It said four soldiers also were wounded in the attack in South Waziristan, a district in the Khyber Pakhtunkhwa province. The army provided no further details, but South Waziristan had served as a militant base until recent years when Pakistan said its operations there had cleared the area of the Taliban.

No group claimed responsibility, although Pakistani Taliban have been blamed for such previous violence in the region, where militants have a presence. According to a recently released U.N. report, more than 6,000 Pakistani insurgents are hiding in Afghanistan, most belonging to the outlawed Pakistani Taliban group, which often attacks Pakistani military and civilian targets.