Two Saudi border guards were shot dead by a man who attempted to cross the frontier into Yemen before he was killed by Saudi forces, the interior ministry spokeman said Tuesday. General Mansur al-Turki said a colonel and a sergeant were shot dead, while another sergeant was wounded by a Saudi national whom they tried to stop from crossing into Yemen in a 4x4 vehicle early Tuesday. He said that security forces followed the man who had a large amount of ammunition and killed him in a gunfight. The rugged borders between restive Yemen and the ultra-conservative kingdom are frequented by drug traffickers. They are also feared to be used as an access point for Al-Qaeda militants who have regrouped in Yemen.