Military sources said the attack was carried out at 6:30 pm when the convoy was heading to Wana, the main town in South Waziristan Agency.
Two soldiers were killed instantly, the sources said. The injured were rushed to a field hospital in Wana.
Security personnel later launched a combing operation in the area, which is infested with militants and has been often been targeted by US drones.
No group claimed responsibility for the attack but such strikes are usually blamed on the Pakistani Taliban.