The Islamist militant group Al-Shabaab claimed responsibility for the attack.
“Our Mujahideen [fighters] based in Mogadishu have today targeted a convoy of foreign mercenaries and their apostate allies nearby the airport,” Sheikh Abdiasis Abu Musab, Al-Shabaab’s military operations spokesman, said.
“The UN convoy was passing outside the airport. Three people died including a policeman and two Somalis who were bodyguards of the UN,” Ahmed Nur, a senior police officer told Reuters. He said 10 people were injured.
Aleem Siddique, a spokesman for UN’s Somalia mission, said no UN staff were killed during the attack.
The airport has a tight security cordon and blast walls, and is used as a base for UN operations in Somalia. The airport area is also the home to the British and Italian embassies.
A security adviser at the airport told Reuters four members of DUGUF, a private security firm, were killed in the blast.
International delegations visiting Mogadishu frequently travel with local security firms which place pick up trucks at the front and back of a convoy, each with about 10 security men armed with AK-47 rifles.
African Union forces along with the Somali army launched a new offensive this year against Al-Shabaab, which is fighting to impose its harsh interpretation of Islamic law on Somalia.
Driven out of Mogadishu in 2011, Al-Shabaab has lost control of several towns in the latest offensive, but officials say the Islamists still control tracts of countryside and settlements from where they have launched their guerrilla-style campaign.