The military's statement came after local people and security officials in the South Waziristan district reported that a suspected US missile strike on a Taliban and Al-Qaeda hideout had killed 13 people, including several Arabs.
Chief military spokesman Major General Athar Abbas told AFP that information from the area indicated that the deaths were caused by explosive material stored in a house.
"As per our information it was an explosion caused by explosive material in a house," Abbas said, adding that the blast reportedly killed 10 to 12 people.
All of their nationalities were not known, he said.
Pakistan has previously disputed reports of US military action in the tribal belt, with Islamabad repeatedly stating that it will not allow foreign forces to operate on its soil.
The latest incident comes a month after Osama bin Laden's operational number three, Abu Laith al-Libi, was killed in a missile strike in the neighbouring Pakistani tribal area of North Waziristan.