At least 15 people were killed and several others injured in a car bomb attack in Wadajir district in Somalia's capital Mogadishu on Tuesday, Xinhua News Agency reported, citing a local official.

The bombing targeted a government building and also destroyed nearby houses.

"There are heavy casualties and the death toll could rise," Ahmed Mohamed Mohamud, a spokesman for the Internal Security Ministry told Xinhua reporters in Mogadishu.

The injured have all been sent to nearby hospitals. Among them is the Wadajir district commissioner, who was inside the building at the time of attack.

A witness told Xinhua that he saw bodies strewn on the floor minutes after the explosion.

Terror group Al-Shabaab has claimed responsibility for the attack, which came barely a week after another attack on a restaurant in Mogadishu claimed 29 lives.

Most of the casualties in the fresh attack were reported to be civilians.

Local residents said the blast sent a tick plume of black smoke into the sky.

Reuters said at least 10 people have been killed, 20 others injured with more than 10 cars destroyed.