Three intelligence officials say the nine people were shot several times in the head and chest. Their bodies were found on Monday off a road in Pir Kili village. They said the dead men were linked to the Pakistani Taliban.
The officials spoke on condition of anonymity because they are not authorized to speak to reporters.
North Waziristan is a hub of militant activity near the Afghan border.
The militants' bodies were found one day after 21 tribal police personnel who had been abducted were found dead in another tribal region.
The incidents illustrate the conflicts among warring factions and militants that plague Pakistan.