Pakistani officials say militants have crossed into Pakistan from Afghanistan and killed 13 Pakistani troops, beheading seven of them.
Military officials said on June 25 that more than 100 militants had crossed the border in the northwestern Upper Dir region the previous night and clashed with Pakistan forces on a patrol.
The military said six soldiers were killed outright.
Seven, who were missing, were killed and then beheaded, while another four still have not been found.
The claim could not be independently verified.
Some intelligence officials blamed the attack on loyalists of Pakistani cleric Maulana Fazlullah, who fled to Afghanistan after losing control of Swat Valley, where Pakistan defeated a local Taliban insurgency in 2009.
Islamabad has complained that militants use parts of Afghanistan as a sanctuary to stage attacks inside Pakistan.
Based on reporting by AFP and AP