Pakistan's military says a roadside bomb has killed four members of the country’s security forces and wounded three others in the northwestern Kurram tribal area.
A statement said that the improvised explosive device went off on October 15 near Kharlachi, a border crossing with Afghanistan.
Unidentified security officials were quoted as saying up to three bombs went off in the attack, which was claimed by the Pakistani Taliban. Officials told the AFP news agency that the search party belonged to the paramilitary Frontier Corps.
The army statement said the troops were taking part in a search operation for the militants who had held an American-Canadian family that was rescued last week after almost five years in captivity.
It said the dead included an officer.
Kurram is one of the seven agencies in the Federally Administered Tribal Areas (FATA), a semiautonomous tribal region of Pakistan adjacent to Afghanistan’s Nangarhar Province.
On October 11, Pakistani soldiers rescued U.S. citizen Caitlan Coleman, her Canadian husband, Joshua Boyle, and their three children in Kurram after the military received intelligence from U.S. officials.
Coleman and Boyle were kidnapped while backpacking in Afghanistan in 2012. The couple's three children were born in captivity.
The family had been held by the Afghan Taliban-aligned Haqqani network.
After landing in Canada late on October 13 with his wife and children, Boyle accused the kidnappers of murdering their infant daughter and raping his wife.
President Donald Trump has praised Islamabad for acting on the U.S. intelligence tip and showing its willingness to "do more to provide security in the region."
U.S. officials have long accused Pakistan of ignoring the presence of the Haqqani network and other extremist groups within its borders.
With reporting by AFP, AP, Dawn, and RFE/RL's Radio Mashaal