Pakistan's support is crucial to US efforts to stabilise Afghanistan, but cross-border raids have raised tension between Pakistan and Afghanistan in recent months.
Soldiers of the Chitral Scouts and police were among the dead in the string of attacks that began with an assault on paramilitary check posts in the border village of Arandu in the northwest just across from Afghanistan's Nuristan province.
"Reportedly, terrorists from Swat, Dir and Bajur organised by Fazullah and Maulvi Faqir Mohammad with local Afghans have attacked the security forces posts," a military statement said.
A senior Chitral Scouts official, Haroon Rasheed, said 26 soldiers and 10 border police were killed.
Twenty militants were also reportedly killed when insurgents attacked seven military check posts, the military statement said. There was no independent verification of the militant death toll.
The military statement put the security forces death toll to at least 25.
Troops blew up two bridges in the border region to stem the militants' incursion.
"Scanty presence" of NATO and Afghan forces along the border has enabled militants to use these areas as safe havens and launch repeated attacks inside Pakistan, the military said.
Copyright Reuters, 2011