NATO's International Security Assistance Force said the blast was on a road close to the Kabul International Airport and that initial reports indicated it might have been set off by a suicide bomber, CNN reported.
The Afghan Interior Ministry said the incident occurred on Qasabah road, north of the airport, the report said.
It was not immediately known if there were any other casualties.
The airport area has been the target of the militants.
In June, security forces killed Taliban insurgents carrying guns and explosives after the attackers took over a building near the airport.