An explosion at a tourist site in southern Yemen killed four South Korean tourists and a Yemeni man on Sunday, a Yemeni security official said. There were conflicting reports about the nature of the bombing, with one security official saying it was a suicide attack and another saying it was a roadside bomb detonated by remote control. They spoke on condition of anonymity because they were not authorized to talk to the media. A South Korean Foreign Ministry official confirmed the tourists were killed in the attack. He spoke on condition of anonymity in line with ministry policy. The Yemeni Ministry of Tourism said the dead South Koreans included two men and two women. Their Yemeni guide was also killed in the attack, which wounded four other foreigners and an unspecified number of Yemenis, said the ministry's statement. He said police were investigating the cause of the blast, which injured three other South Koreans, in the city of Shibam in the southeastern province of Hadramout. He said the explosion occurred as the tourists visited the city dubbed the “Manhattan of the desert” - a Unesco World Heritage site famous for its 16th-century tower houses which were made with mud bricks and rise up to 16 stories high.