According to official sources, a firefight between Islamic militants and government forces broke out overnight in Southern Waziristan, along the Afghan border. Both sides were said to have deployed heavy machineguns and grenade launchers.
Two local residents were killed when a stray grenade hit their home. It was not reported whether the militants suffered any losses.
Clashes were also reported in Northern Waziristan, injuring at least six soldiers.
Northern and Southern Waziristan are virtual no-go areas for government forces. The mountainous region is the stronghold of fiercely independent Pashtun tribes, and it is believed to be a safe haven for hundreds of Taliban fighters.
U.S. officials have said they believe the area may also be the hiding place of al-Qaeda leader Osama bin Laden.