There was no immediate claim of responsibility but in the past similar attacks against the United Nations (UN) have been carried out by al Shabaab militants who are allied with al Qaeda and want to topple the Western-backed government in Mogadishu.
“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 advisor 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.