<text>  CNNThe terrorists who attacked the Bardo Museum in Tunis, Tunisia, last week were wearing suicide vests but failed to detonate them before being gunned down by police, Tunisias President told CNN. They had them, but they didnt work, because the police turned up and they were shot down and they didnt have the time to get these vests to work. Because had they done so, we would have had major catastrophe, President Beji Caid Essebsi told CNNs Christiane Amanpour. A third museum attacker remains at large, Essebsi said. Previously two suspects had been identified -- Yassine Labidi and Saber Khachnaou -- though it wasnt immediately clear if they were the pair killed at the museum by Tunisian security forces. Essebsi told Amanpour 15 arrests had been made since Wednesdays attack, in which 23 people were killed. Most of the victims were foreigners and 19 were tourists whod been on two cruise ships that docked in Tunis. Essebsi said he believed the attackers were members of ISIS who had been trained in Libya. This echoed comments made by Tunisias Security Minister Rafik Chelly on Friday, who said two attackers had been given weapons training at Libyan camps and had been activated from sleeper cells. In an audio message posted online Thursday, ISIS claimed responsibility for the attack. The message said the group had targeted crusaders and apostates with automatic weapons and hand grenades in bloodshed that was just the start. CNN cannot independently verify the legitimacy of the audio statement. An uncle of suspect Yassine Labidi, Abeld Malik Labidi, told CNN on Friday that no one he knew had seen any signs of extremism in his 26-year-old nephew. He said Yassine Labidi was one of the two gunmen killed at the museum. Its true that Yassine carried out this terrorist attack, he was killed; his head, his body, we dont have it back, he said. But, he said, he believed Yassine and other young Tunisians like him were also victims of terrorism -- of the recruiters who paid them money, organized the logistics and took them to places like Syria and Libya to train as fighters. Laura Smith-Spark and Claudia Morales contributed to this report. 