Deputy Secretary-General Jan Eliasson (right) meets with Fowsiyo Yusuf Haji Adan, Deputy Prime Minister and Minister for Foreign Affairs of the Somali Republic.

At least 14 people died and 15 others were wounded in an attack on the U.N. headquarters in the Somali capital of Mogadishu on Wednesday.

Seven militants, four U.N. employees and three female civilians were killed, said Abdikarim Hussein Guled, the country's interior and national security minister. The other victims were rushed to a hospital.

Al-Shabaab, the militant group linked to al Qaeda, claimed responsibility, the group said on Twitter. It was the second major attack in the city in less than a month in an unstable nation beset with civil strife for many years.

Police Officer Hussein Ahmed said one attacker blew himself up at the entrance of the U.N. compound, which is near the city's airport.

Others wearing suicide vests entered the U.N. compound. He said Somali and African Union forces surrounded the building and fought with the armed assailants.

The strike devastated the area. Mangled buses and cars sat in disfigured heaps, the windows of nearby apartments shattered, the ground littered with blood and body parts.

A large brown plume of smoke was visible in the air as ambulances rushed to the scene and carried away the wounded.

The compound has now been secured and is in the hands of AU troops, the official Twitter account of the African Union Mission to Somalia said.