An Interior Ministry official said attackers hit Tikrit's Tasfirat prison Thursday after detonating car bombs and fighting with authorities, CNN reported Friday.
The BBC reported 12 guards were killed and 90 inmates escaped. Iraq's state-run National Iraqi News Service reported at least 26 security officers were killed or injured but it didn't distinguish between those killed and those hurt.
Some inmates attacked guards and held the prison warden hostage while others escaped, officials said. Attackers gained entry to the facility by wearing police uniforms and driving cars similar to those used by police, a police source told the Iraqi news service.
Security forces surrounded the prison and fought to regain control, the Interior Ministry official said.
Ahmed Abdallah al-Jabouri, governor of Salaheddin province, said security forces arrested 33 inmates who had escaped.
Tikrit, northwest of Baghdad, was under a curfew.