The Qatari delegation was unharmed and safely reached their hotel, but four civilians and a soldier died in the attack.
Soldiers fired in the air to disperse crowds that had gathered at the blast site at the busy KM4 junction. The car bombing has been blamed on the Islamic extremist group al-Shabab, which has been pushed out of much of the areas it occupied in south and central Somalia by African Union troops.
Meanwhile, a woman died and 44 people were seriously injured when a bomb exploded in a Roman Catholic Church in northern Tanzania. The regional police commissioner said eyewitnesses reported that the bomb was thrown from a motorcycle into the church.