Nigerian authorities say 252 inmates are on the run after gunmen attacked a prison in the central city of Jos.
Nine detainees, one prison staff member and one of the gunmen were killed during Sunday's raid, the Correctional Service said in a statement.
At least 10 inmates who fled were rearrested.
The attacked prison is located in an area housing the state headquarters of the country’s security agencies, including the police.
Armed groups - sometimes trying to free their detained members - have frequently targeted Nigeria’s crowded prisons.
More than 800 inmates were freed after gunmen raided two other facilities in recent weeks.