Gunmen attacked the African Union's main base in the capital, Mogadishu, leading to an exchange of gunfire between militants and soldiers on Thursday, an official and a witness said. According to AP, Somali militant group al-Shabab said they were responsible for the attack and were targeting a party at the base near the capital's airport, which also houses U.N. offices, among others. Gunfire and explosions could be heard, and the militants may have entered the base, said Mohamed Abdi, a policeman at the capital's airport, which shares a fence with the AU base.