Pakistan's military says heavy fire from across the Afghan border killed seven Pakistani soldiers Tuesday.
The attack hit a paramilitary force outpost in South Waziristan's Angoor Adda region.
The military did not say whether militants or Afghan soldiers were responsible, and there was no immediate comment from Afghanistan.
The neighboring countries have in the past accused each other's forces of initiating cross-border fire.
In August, Pakistan summoned Afghanistan's ambassador to Islamabad to protest what it called "unprovoked" shelling that killed three Pakistani soldiers. A day earlier, Afghanistan summoned Pakistan's ambassador to say shelling from Pakistani troops had killed eight Afghan soldiers.
Pakistan has complained that fugitive insurgents linked to the Pakistani Taliban have taken refuge in Afghan border areas where they plan and stage cross-border attacks. Afghan has also long accused Pakistan's powerful military of covertly supporting the Taliban insurgency in Afghanistan.
