Gunmen on a motorbike shot dead an intelligence officer on Monday in Sana'a, the Defense Ministry's website reported.A security official told the website that Ahmed al-Najdi and Mohammed al-Uraij, colonels in the political security service, were targeted by two gunmen on a motorbike.The official said that al-Najdi was dead immediately and al-Uraij was wounded and admitted to the hospital.The attackers have escaped, he added.