Gunmen ambushed a prison convoy in the Yemeni capital Sana'a today, in a failed attempt to free an arms dealer and former government negotiator with Huthiyeen, dpa quoted police and medical sources as saying. The assailants opened fire at the convoy of eight vehicles ferrying Faris Manna as it raced between a jail and the state security court, a police source told the German Press Agency dpa. The source, who requested anonymity, said the attackers fired automatic machineguns from the roof of the four-story headquarters of Manna's trading company near Sana'a University. An intelligence officer in the convoy was injured and was in critical condition, he said, adding that policemen in the police cars fired back. Medical sources said a passer-by died in hospital of injuries suffered in the shootout. A woman was also injured in the firefight, and her condition was stable, the sources said. Security authorities sent armoured personnel carriers to back up the convoy carrying Manna back to jail, witnesses said. Manna was being transferred to gain prosecution's permission to extend his detention for 25 days, court officials said. The Yemeni government and the insurgents reached a cease-fire agreement on February 11 that ended a five-and-a-half-year conflict.