The Toledo Correctional Institution was on lockdown for more than six hours Tuesday after multiple anonymous threats were made to the prison.

The telephone threats, made to "anyone who would answer" started about 7 a.m. and continued until about 12:30 p.m., at which time the prison was locked down, said the prison's spokesman, Meredith Rinna.

The Ohio Highway Patrol and Toledo police searched the premises and did not find anything to validate the threats, and the lockdown was lifted at 6:45 p.m., she said.

Ms. Rinna declined to comment on the nature of the threats but said there were "multiple things threatened." She described them as "general security threats."

She also would not comment on whether the caller was a man or woman.

Ms. Rinna said the entire staff of 344 employees and the facility's 1,400 inmates were accounted for before the search.

During the lockdown, visitors were not allowed at the facility and no new prisoners were allowed in. Inmates were confined to their cells until the lockdown was lifted, Ms. Rinna said. Employees were allowed to come and go, she added.

On Tuesday evening, dogs brought in by helicopter from Columbus were sniffing near tractor-trailers and trash bins at a warehouse on the grounds, and large groups of police, troopers, and prison staff searched outside.

Vehicles were turned away and the occupants told they could return today.

In November, the prison received information that there was a "crudely made gun" inside the facility, but an extensive search did not substantiate the claim, Ms. Rinna said.

First Published May 1, 2012, 8:37 p.m.