The explosion happened near a defence ministry hospital, and heavy gunfire was heard soon after.
UAE ambassador Mohamed Al Othman was present in the vehicle when it was targeted, but he is said to have survived the attack.
The suicide car bomb hit one of convoy leaving behind 5 people killed including civilians. Three others were injured who were rushed to hospital.
Reliable Reports state that a young girl sustained injuries after AU forces opened fire indiscriminately on the civilians who happened to be near the scene.
No group has claimed the responsibility for attack though Al Shabab vowed to step up attacks against the government of Somalia during the month of Ramadan.
Somali government and the ambassador did not comment on the incident.