NAIROBI, Kenya — A suicide bomber detonated explosives on Monday in a vehicle at the gate of district headquarters in Mogadishu, the Somali capital, killing at least six people, the authorities said.

Capt. Mohamed Hussein of the police said the large blast had badly damaged the headquarters of the Hodan District.

The Aamin Ambulance service said that at least six people had died and that 16 others were wounded. Captain Hussein said most of the victims were district workers and soldiers.

It was the second significant attack on seats of government in the capital this month. At least six people, including two children, were killed at Howlwadag District headquarters on Sept. 2, shattering a period of calm in the city