Sentries at the Zarai Noor army camp in Wana, the main town of South Waziristan, spotted the two suicide attackers in their vehicle when they were about 100 metres from the camp early this morning, military sources said.
The troops opened fire and both suicide attackers were killed when the vehicle blew up, the sources said, adding two soldiers were also killed and four more injured in the incident.
No group claimed responsibility for the attack.
Such incidents are usually blamed on the banned Tehrik-e-Taliban Pakistan.
Yesterday, nine people were injured when a suicide attacker rammed his explosives-laden vehicle into the gate of a police station in Bannu town of Khyber-Pakhtunkhwa province, which is located a short distance from North Waziristan.