Somalia\'s Al-Qaeda linked Shebab insurgents ambushed President Hassan Sheikh Mohamud Tuesday, the militants said, claiming to have destroyed vehicles with rocket-propelled grenades. \"We ambushed a convoy that was escorting the self-appointed Somali president,\" Shebab spokesman Abdulaziz Abu Musab told AFP, adding that fighting was continuing near the port of Merka. There were no immediate reports of any casualties.