A bomb has exploded in the Somali capital Mogadishu with reports that several people were killed.The blast took place on a road by the entrance to a camp for the Somali Air Force which is close to the international airport. Although it is not yet clear who was behind the attack, the Islamist militant group Al Shabab frequently carries out suicide bombings. Somalia is also in the middle of a political crisis due to a power struggle between the president and prime minister ahead of elections.