The governor and security director of the southern Yemeni city of Aden escaped a gun attack on their convoy on Tuesday, a security official said, the latest in a string of militant attacks on the government. Three of the gunmen were killed in an exchange of fire, while two bodyguards and two civilians walking by were wounded, the official said. But Governor Aidarus al-Zubaidi and Brigadier General Shalal Ali Shayyeh were unhurt. Both men have survived attacks before. UN warns of famine in besieged Yemeni city The UN is warning of famine in the Yemeni city of Taiz, which has been besieged by Shiite Houthi rebels for months. The World Food Program (WFP) said Monday that Taiz "is in the grip of severe food insecurity at ‘Emergency' level - one step below famine." The UN agency says it delivered enough aid to part of the city on Saturday to support 3,000 families for one month. The central city of Taiz has been a major battleground between the Houthis and forces allied with the internationally recognized government. The rebels are allied with army units loyal to a former president. Meanwhile, a drone attack on two public buildings controlled by Al-Qaeda militants in south Yemen killed three people on Monday, a local official said. The dawn attack also badly damaged the offices of public water and telecommunications utilities in Huta, capital of Lahij province, the official added. No details about the three victims were immediately available. Witnesses said two drones overflew Huta both before and after the attack. The drone strike came a day after a soldier and a civilian were killed in a suicide car bombing in Huta that a Yemeni military source said targeted an armored vehicle of the Emirati armed forces. The United Arab Emirates has lost more than 70 soldiers in Yemen since the Saudi-led Arab coalition last March launched a military campaign in support of President Aberabbu Mansour Hadi's internationally recognized government. Lahij is one of five provinces retaken from Iran-backed Shiite Houthi rebels last summer by pro-government forces, but security problems persist.