NewsRadio 920 WHJJ and the Associated Press

CRANSTON, R.I. (AP) — Rhode Island's maximum security prison in Cranston was locked down for about 2½ hours after officials found a note threatening the killing of a correctional officer.

Prison officials say the anonymous note was found Thursday at the Adult Correctional Institutions prison and authorities locked down the facility while they searched inmates' cells for weapons and other contraband. A Department of Corrections spokeswoman says nothing was found during the search and it remained unclear who wrote the note.

The correctional officers' union says the note was written by an inmate with ties to a "notorious gang" who threatened to kill a correctional officer and retaliate against other prison guards. The union didn't name the inmate.

Union officials say there were more than 150 incidents of inmate violence in January and February.