An extensive police manhunt is under way after a prisoner who was serving a 10-year sentence for robbery escaped on Sunday from a facility in Shenzhou city, North Hebei province, provincial authorities said on Wednesday.

The prisonbreak was officially confirmed on Sept 13.

An unnamed official from the prison confirmed on the phone that a breakout did happen on Sept 11, 2011, the Beijing News reported Wednesday. The police is hunting the escaped prisoners.

Most of the prisoners confined in the jail are serious criminal offenders. The official denied the death of any prison guards during the breakout.

A resident of Gaoguzhuang village near the jail saw a lot of armed police officers suddenly appear on the land surrounding the prison and at nearby roads to check passing vehicles on the morning of Sept 11.

Some villagers said the breakout may have happened at 4 am that morning.