At least 15 people have been killed and more than 20 people injured when a car bomb exploded near a cafe in Somalia's capital, Mogadishu, officials say.

The vehicle was parked close to the Hotel Muna, often frequented by Somali politicians and itself the target of an attack by militants in August 2010.

The al-Shabab group said it carried out the Wednesday afternoon blast.

But the militant Islamists denied that it was a suicide attack as earlier reported by the police.

The attack is the latest of a series of suicide attacks staged by the al-Qaeda-linked group in Mogadishu - after being pushed out last August by the Somali government and African Union troops, BBC News reported.