The incident took place in old airport in eastern Khost city after a suicide bomber detonated explosives packed in the vehicle near the eastern gate of the airfield.
Taliban group claimed responsibility behind the incident and said the main target of the suicide bomber was a joint military base used by Afghan and coalition security forces.
Afghan interior ministry spokesman Sediq Sediqqi said the attack was a suicide car bombing and happened near the entrance of Camp Chapman base in Khost, close to the border with Pakistan.
In the meantime a local police official said the assailant struck Wednesday as the convoy was traveling to the airport near the capital of Khost province, which borders Pakistan. NATO command could not confirm the attack and Afghan authorities had no further details.