A suicide bomber killed 18 people including three Somali government ministers at a ceremony in a Mogadishu hotel on Thursday, officials said. The blast is the most serious attack on the transitional federal government (TFG) since the launch of an Al-Qaeda inspired Islamist insurgency that has brought new strife to the Horn of Africa nation. Several ministers from the UN-backed government were at a graduation ceremony for students at the Shamo hotel when the explosion went off. A security official said 18 people were killed and that the blast was caused by a suicide bomber. "Most of the vicitms were students," the official said. A hotel security official said the suicide bomber was probably hidden among the guests. Higher Education Minister Ibrahim Hassan Addow and Health Minister Qamar Aden were killed on the spot and Education Minister Mohamed Abdullahi Waayel died shortly after the blast, a senior government official said. Sports Minister Suleyman Olad Roble was among the injured, the official added.