CHITRAL, Pakistan Several hundred militants from Afghanistan launched a pre-dawn cross-border raid on Pakistani paramilitary posts on Saturday, killing up to 36 people, government and security officials said.
Pakistan's support is crucial to U.S. efforts to stabilize 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 Chitral district just across from Afghanistan's Nuristan province.
"Reportedly, terrorists from Swat, Dir and Bajaur organized by Fazullah and Maulvi Faqir Mohammad with local Afghans have attacked the security forces posts," a military statement said, referring to northwestern Pakistani regions and senior Pakistani Taliban commanders.
Many Pakistani Taliban fighters fled to Afghanistan in the face of army offensives and have joined allies there to regroup and threaten Pakistani border regions, analysts say.
The military operations in the country's northwest have inflicted heavy losses on them, but insurgents have proved resilient with intermittent attacks and suicide bombings.
A senior Chitral Scouts official, Haroon Rasheed, said 26 soldiers and 10 border police were killed.
Twenty militants were also reportedly killed when up to 300 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 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.
Twenty-seven Pakistani servicemen were killed and 45 militants died in clashes in July when some 600 militants from Afghanistan attacked two Pakistani villages in Dir.
Pakistani Taliban later claimed responsibility for the Dir attack, part of seemingly new militant strategy of carrying out large-scale attacks on government and army targets.
Militants have largely relied on a campaign of suicide and bomb attacks that have killed thousands of people across the country.
Pakistan has blamed Afghanistan for giving refuge to militants on its side of the border.
On Saturday, the country's foreign office summoned the Afghan charge d'affaires to lodge a protest over the cross-border raid.
"It is Pakistan's expectations that ISAF and the Afghan National Army would take effective measures to prevent such incursions by militants from safe havens across the border," a foreign office spokesperson said in a statement.
Kabul has also blamed Pakistan in recent months for killing dozens of civilians in cross-border shelling.
(Additional reporting by Saud Mehsud and Augustine Anthony; Writing by Augustine Anthony; Editing by Chris Allbritton)