Heavy fighting involving artillery fire and helicopter gunships has been reported in the Pakistan tribal area of North Waziristan.
The army said that it killed at least 23 fighters on Wednesday night, but the BBC reports there was no independent confirmation of these figures.
Military sources said a convoy of security forces was ambushed while returning from Khajori.
The convoy was carrying soldiers wounded when a suicide bomber in a truck drove into the base during prayers at a mosque there. Five other soldiers were killed by the bomber.
The post and and a nearby fort guard the main highway that connects the town of Miranshah in North Waziristan with Bannu, a city in Khyber Pakhtunkhwa province.
