听力原文： Prison service staff here in Britain has been severely criticized in an official report for escape of five Iraqi prisoners and an armed robber from Whitewall Prison in Kenbershire. Bomb-making equipment was subsequently discovered in the jail. The government has announced a major review of prison security of England and Wales. A new task force was set up at the Home Office and detailed recommendation is expected to be issued by the end of the year. The number of escaped prisoners is ______.