Several people were killed or wounded on Saturday when gunmen opened fire then detonated a car bomb on a busy road in Somalia's capital Mogadishu, police said.

"There was a drive-by shooting attack... then a car loaded with explosives was detonated after police reinforcements arrived," police official Ahmed Abdiweli told AFP.

"Most of the casualties are civilians."

Witnesses said gunmen first opened fire on a Somali government official's car, sparking a gun battle with his security escort.

"The gunmen riding in a car attacked the official and there was exchange of gunfire... then there was a huge blast," said Abdi Mudey, who was near Makka al-Mukarama Road where the attack took place.

"I saw several people who were seriously wounded."

There were no immediate claim of responsibility, but Somalia's Shebab insurgents have carried out a string of attacks in the capital.

Expelled from Mogadishu in mid-2011, the Al-Qaeda-linked Shebab still hold swathes of the countryside which they use as launching pads for their attacks.

They are fighting to overthrow the internationally-backed government in Mogadishu, which is protected by a 22,000-strong African Union force.
Source: AFP