MOGADISHU, Somalia 

Bombings followed by gunfire in Somalia's capital targeted the Banadir Regional Administration headquarters on Sunday, with multiple casualties feared, an official said.

Abdifatah Ilmi, a security official in Mogadishu, told Anadolu that authorities suspected the attack involved three heavy explosions before armed men stormed the heavily fortified municipality headquarters.

"It's very early to say how many people have been killed or wounded but there are casualties and the attack in ongoing," Elmi said.

Nimco Ahmed Bashir, an eyewitness and street vendor who also told Anadolu that she saw several wounded people.

Al-Qaeda-affiliated terrorist group al-Shabaab claimed responsibility for the attack and said its fighters stormed the office of Mogadishu's mayor.