An explosion Wednesday at a ceremony at Somalia's national theater killed at least 10 people including two top sports officials in an attack by an Islamist group on a site that symbolized the city's attempt to rise from two decades of war. The explosion at the newly reopened theater happened as Somali Prime Minister Abdiweli Mohamed Ali was standing at the podium to deliver a speech. The prime minister was unharmed, said Abdirahman Omar Osman, the government spokesman. The president of Somalia's Olympic committee and the president of its soccer federation were killed, according to Shafici Mohyadin, the federation's secretary. The blast shattered a tentative peace that descended on Somalia's capital, Mogadishu, after fighters belonging to the Islamist group al-Shabab were pushed out last August by government and African Union troops. The government said a female suicide bomber carried out the attack, but al-Shabab, using its official Twitter feed to claim responsbility for the attack, said explosives had been planted in the theater before the event. Sports leagues have blossomed and seaside restaurants have been setting up shop, marking a long-awaited a revival of the seaside capital. Wednesday's ceremony — two weeks after the theater reopened — was held to mark the first anniversary of the start of a national TV station. The blast cut chairs in half, filled the room with smoke and splattered blood across the walls. "It was a cowardly act and that will not deter the government from performing its national duties," Osman said. "The prime minister will energize the government to eliminate the terrorists out of the country."