No group claimed responsibility for the December 20 attack, although officials have blamed similar incidents in the past on the Taliban.
Afghan policemen inspect the site of the blast, which President Ashraf Ghani blamed on "the enemies of Afghanistan."
The force of the explosion shattered windows in nearby buildings.
Officials warned that the death toll could rise, adding that all the casualties were civilians.
An injured man sits inside his damaged vehicle.
The blast set surrounding civilian vehicles on fire, and also damaged nearby buildings and shops.
Members of the Afghan security forces inspect at the site of the attack.
An Afghan journalist films a damaged vehicle at the site of a blast in Kabul on December 20.
Afghan security personnel inspect the site of the explosion, which occurred as the Wardak's convoy was passing through an intersection in Kabul's Khushal Khan neighborhood.
Members of the Afghan security forces stand guard at the site of an attack in Kabul on December 20.
Afghan policemen inspect at the site of the explosion.
Afghan men look out a damaged window of an apartment that faces the scene.
Television footage showed at least three cars on fire.
Members of the Afghan security forces stand guard at the site of the attack.