According to the authorities, al-Qaida-linked militants raided a regional government office in Somalia's capital on Sunday (Jan.22), killing five people.
Abdulkadir Adan, the founder of the Aamin ambulance service, told The Associated Press that his crew rescued 16 injured persons from the area.
The al-Shabab terrorist organisation claimed credit for the attack on Mogadishu's Banadir Regional Administration offices.
The incident began with a suicide bombing, according to a staff member at the headquarters, before gunmen entered and exchanged fire with security personnel.
The majority of the workers, according to Mustafa Abdulle, were rescued by security forces.
Al-Shabab frequently conducts attacks in Mogadishu.
The federal government declared "total war" on the extremist organisation last year and has retaken a number of villages in central and southern Somalia that the fighters had occupied.