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.A police commander told the BBC it was a suicide attack. 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 Islamist militant group al-Shabab has said it carried out the Wednesday afternoon blast. 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.The BBC’s Mohammed Dhore in Mogadishu says that seven people died at the scene.Mogadishu Mayor Mohamed Ahmed Nur said the blast had killed 15 "innocent civilians”.Our correspondent says people were drinking tea at a popular cafe in the heart of Mogadishu’s government district, when the bomb exploded."There was a heavy explosion, a car full of explosives was detonated,” MP Mohamed Iro told the AFP news agency. The attack took place on the day of a visit to the city by the European Union’s new special envoy to the Horn of Africa, Alexander Rondos.Last week, William Hague was also in Mogadishu, the first visit by a British foreign secretary in 20 years.Agencies