At least six people, including three civilians, have been killed in a suicide bombing at a local government office building in Somalia's capital, officials say.

Sunday's car bomb attack destroyed the building in Mogadishu and caused a nearby school to collapse.Plumes of smoke were seen rising from the scene.

Three of the people killed in the blast were security forces who stopped the bomber fromspeeding through a checkpoint, Salah Hassan Omar, spokesperson for the Mogadishu administration, told reporters at the scene.

The attacker then detonated the explosives-laden vehicle near the gate of Hawlwadag district headquarters, Omar added.

The three others killed in the explosion were civilians, Omar added.

Fourteen people, including six children, were critically wounded, according to the city's ambulance service. Among the wounded was Ibrahim Hassan Matan, deputy district commissioner.

Most of the wounded were young students from the nearby Quranic secondary school, according to officials. The school was open at the time of the attack but most of the children were away from the building on a break.

"I saw bodies strewn on the ground after the explosion before the ambulances and the paramedics reached the scene and the whole scene was very ugly," witness Halima Mohamed told The Associated Press news agency.

Police Captain Mohamed Hussein said that, despite the fatalities, the attacker had "failed to achieve their goal of inflicting maximum casualties".

The blast also blew off the roof of a mosque and damaged homes nearby, prompting officials to warn that more casualties could be expected. (Aljazeera)