At least five soldiers and 21 Taliban insurgents were killed on Monday as Pakistani forces fought off fierce attacks on two of their checkpoints near the Afghan border, security officials said.
About two dozen militants armed with assault rifles and rocket-propelled grenades raided a checkpoint in the Mattak area of the Bajaur tribal district, triggering an intense fight that left four soldiers dead and two wounded.
"The security forces successfully repulsed the attack, killing six terrorists and injuring four others," said a local intelligence official who spoke on the condition of anonymity.
Pakistani forces are carrying out an operation against Islamist insurgents in Bajaur, one of the seven tribal districts where the Taliban and Al Qaeda have safe havens.
Amid government claims of success, the Taliban have continued its attacks on government and civilian targets. On Sunday, the militants claimed they had shot down an army helicopter in Bajaur, killing six soldiers.
But the army's chief spokesman, Major General Athar Abbas, said the chopper made a crash landing after developing a technical fault. The two pilots survived.
Separately, 15 Taliban were killed Monday during an attack on a security post in Hangu, a district in the North-West Frontier Province, which borders the ungoverned tribal region.
The pre-dawn attack in Torawarai village triggered a gunfight that also left one soldier dead and three wounded.
"After exchanging heavy fire, the militants retreated with several comrades injured," police officer Mirzali Khan said over the phone.
Troops pounded suspected militant positions after the attack, but there were no immediate reports of casualties.
Monday's attacks came as more than 30,000 Pakistani soldiers battled several thousand Taliban and Al Qaeda-linked militants in their heartland of South Waziristan.
The military announced its first major victory at the weekend when troops captured the strategic town of Kotkai after days of intense clashes.
Kotkai is the birthplace of Pakistani Taliban chief Hakimullah Mehsud and the hometown of his close aide, Qari Hussain, known as "the mentor of suicide bombers".