Taliban militants attacked two Pakistani security posts in a tribal area bordering Afghanistan on Monday, sparking fierce clashes in which 20 rebels were killed, officials said.
The hardline fighters attacked a paramilitary fortress and stormed a checkpost in the semi-autonomous Bajaur tribal zone, a known haunt of Al-Qaeda and Taliban rebels, they said.
The fresh attacks come after a week of some of the most intense clashes seen in Bajaur since Pakistani forces entered the tribal belt in 2001 to hunt down Islamic militants.
"The Taliban launched a big attack on Tor Ghundi fort and Iskandro post. Security forces responded and 20 militants were killed," a paramilitary official told AFP.
There was no immediate information about casualties to security forces.
Residents said the fighting erupted at 1:00 am on Monday and bodies were scattered across farm land some 20 kilometres (12 miles) east of Khar, the main town in Bajaur.
Army helicopter gunships and jets pounded militant positions, they said.
Pakistani military officials said on Sunday that nine soldiers and 100 militants had been killed in four days of fighting.