Iraqi officials say 22 suspects facing terrorism charges have escaped from a jail in northern Baghdad after killing a security guard.

Two senior security officials say a manhunt for the prisoners resulted in the killing of one and the arrest of 13 others. Eight are still at large.

The officials say the detainees killed the guard and escaped early Friday by a backdoor at the detention center in Baghdad's al-Adela prison.

Another guard says several guards were subsequently detained and are being questioned as possible accomplices. All officials spoke on condition of anonymity because they are not authorized to talk to media.

Jailbreaks are frequent in Iraq and, as with other security breaches, have cast doubts on the ability of the authorities to secure the country, mired in sectarian tensions.