At least eight killed in Somali capital car bomb

"We've counted at least eight dead so far. It was a car bomb attack near the National Theatre," said police official Mohamed Duale.

No group immediately claimed responsibility for the blast, but Al-Qaeda-linked Shebab insurgents have launched a series of guerrilla-style attacks in Mogadishu.

"Many have been killed, some of them were in a minibus that was hit by the blast," said Hassan Salad, who witnessed Monday's attack.

"This is a disaster, there is smoke and dead bodies thrown all around."

The insurgents have vowed to topple President Hassan Sheikh Mohamud, who took office last year after being chosen by the country's new parliament.

While the Shebab in recent months have been on the back foot in Somalia, having lost a string of key towns to a 17,000-strong African Union force fighting alongside Somali soldiers, they remain a potent threat.

Large rural areas remain under their control and they have carried out a series of guerrilla attacks in areas supposed to be under government control.

On Sunday the Shebab retook the southern town of Hudur -- the capital of Bakool region -- after Ethiopian troops pulled out of the town.

The recapture of Hudur marks a sharp turnaround for the Shebab as the first territorial victory for several months.

Mogadishu has been rocked by several small attacks -- including both car bombs and suicide attackers -- in recent months.