Reports from Somalia say at least one person was killed and three others wounded in a mortar attack on the main airport in the capital, Mogadishu.
It was not immediately clear who was behind Wednesday's attack, which came minutes after a United Nations delegation arrived at the airport.
Meanwhile, A U.S. official has confirmed that the United States carried out a second air strike on suspected al-Qaida targets in southern Somalia this week.
The official, who spoke to VOA on condition of anonymity, says a C-130 gunship carried out the attack - the same type of aircraft that carried out a similar attack earlier this month. He would not say where the attack was made or which day.
Pentagon spokesman Bryan Whitman would not confirm the new attack on the record.
On Tuesday, Ethiopian troops began pulling out of Mogadishu in anticipation of the deployment of 8,000 peacekeepers from the African Union.
Ethiopian Prime Minister Meles Zenawi says the withdrawal is being timed to coincide with the arrival of AU forces, to ensure there is no security vacuum.
Somali interim government troops and Ethiopian forces seized control of Mogadishu and surrounding areas late last month, after a two-week battle against the Islamic Courts movement.
The Islamists who fled Mogadishu have threatened to wage a guerrilla war against the interim government and Ethiopian troops still in the country.
Somalia has been without an effective central government since warlords overthrew dictator Mohamed Siad Barre in 1991.