Three pro-Taliban fighters were killed and three soldiers, including a captain, injured in a clash that erupted when militants attacked a convoy of security forces in North Waziristan tribal region of Pakistan on Sunday.
The militants fired rockets at the convoy, triggering an exchange of fire near Miranshah, the main town of North Waziristan Agency, which lasted nearly two hours.
An army captain and two other personnel were injured in the exchange of fire. The injured were airlifted to a military hospital in Bannu city of Khyber-Pakhtunkhwa province.
The clash occurred a day after a US drone strike in the same region killed 10 militants. The clash began when security forces began demolishing an orchard that officials said was being used by the rebels for attacks on troops.
A shell hit a vehicle carrying militants, killing three of them, a journalist from the region said. Another shell landed on a mosque at Zafar Town area of a market in Miranshah, injuring around 20 people, he said.
Announcements made on the mosque's loudspeaker asked people to help in shifting the injured to hospital.
An emergency was declared in the main hospital of the area. Local residents said shells also hit houses and vehicles, causing fires.
Security forces had earlier imposed a curfew in North Waziristan.
Authorities usually clamp curfew every Sunday to facilitate the movement of troops in the region.
The residents said some people had fled to other places as there had been no let-up in the exchange of fire.
It was not clear which militant faction was involved in the fighting.
The main Taliban faction in North Waziristan, which is led by Hafiz Gul Bahadur, had struck a peace deal with the security forces in 2007.
A reporter in Miranshah said on phone that Bahadar's group had denied involvement in the violence.
Bahadar's group is also not part of the Tehrik-e-Taliban Pakistan.
US and Afghan officials have described North Waziristan as the main stronghold of Al Qaeda and Taliban elements, including the Haqqani network that launched cross-border attacks in Afghanistan.
Pakistan has been under growing US pressure to launch a military operation in the region but no decision has been taken as yet.
Drones operated by the Central Intelligence Agency routinely launch strikes in North Waziristan despite strong opposition from Pakistan.