A blast at a graduation ceremony in the Somali capital Mogadishu has killed at least 18 people, including three government ministers. Officials say the blast was caused by a suicide bomber, during a graduation ceremony for 43 students from the local Banadir University. Witnesses said the attack appeared to have targeted government officials. Islamists are fighting the UN-backed government, which controls small pockets of territory in the country. The BBC's Mohammed Olad Hassan, who was at the scene, said there was a huge explosion in the hotel's meeting hall where hundreds of people were gathered for the graduation. Several dead bodies were later lying out on the ground outside the hotel, says our correspondent. Five government ministers were reported to have been in the hotel. Health Minister Qamar Aden Ali, Education Minister Ahmed Abdulahi Waayeel and Higher Education Minister Ibrahim Hassan Addow were all reported to have been killed. Two journalists were also among the dead. 'Intimidation' The Shamo hotel is often used by the few foreigners - aid workers, journalists and diplomats - who still visit Mogadishu. It is in one of the small parts of the city controlled by the government, just 1km from a base of the African Union peacekeeping force, Amisom, in Somalia. Security was light inside the ceremony; the ministers' bodyguards were all waiting outside the meeting hall, our correspondent says. No-one has yet claimed responsibility for the attack. The acting head of Amisom, Wafula Wamunyini, condemned the attack, saying it had been "intended to intimidate and blackmail" the UN-backed government. "We want to ensure everyone we are going to continue with our mission. We are going to continue providing our services," he told the AFP news agency. Somalia has not had a functioning national government since 1991. Source: BBC