Gunmen kill security officer in south Yemen ADEN (Reuters) - Two masked gunmen killed a security officer and his bodyguard in southern Yemen late on Friday in what a security official said was a suspected al Qaeda attack. Colonel Mohammed Abdullah al-Habashy, security adviser in the southeastern Hadramout province, was at a restaurant with his bodyguard in the city of Sayoun when gunmen on a motorcycle opened fire, the security official and witnesses said. No one claimed responsibility for the attack. But the official said he suspected that al Qaeda militants were behind it because of its similarity with the killing of two officers in the province days earlier. Yemen's U.S.-backed government is grappling with multiple security and political problems, including threats from a powerful branch of al Qaeda, a secessionist movement in the south and Shi'ite Muslim Houthi rebels in the north. The United States sees Yemen, which borders oil giant Saudi Arabia and lies near vital shipping lanes, as a front line in its struggle against al Qaeda and has used drones there for years to attack suspected members of the group. Reporting by Mohmammed Mukhashaf; Writing by Rania El Gamal; Editing by Alistair Lyon