state prison

FILE – This June 1, 2018, file photo, shows a control center in the west section of the State Correctional Institution at Phoenix in Collegeville, Pa.
(AP Photo/Jacqueline Larma, File)

HARRISBURG, Pa. (AP) — Pennsylvania's state prisons are on lockdown after staff members at a fourth prison required treatment in recent weeks from exposure to a yet-unidentified substance described as a liquid synthetic drug.

The Department of Corrections announced the step Wednesday, a couple hours after it reported that two guards and three nurses at Albion state prison reported feeling sick and required medical attention.

The department didn't say how long the lockdown will last.