Associated Press - November 5, 2009 2:34 PM ET

SHIRLEY, Mass. (AP) - A unit at the state's maximum security prison in Shirley is locked down after four correction officers were injured in a scuffle with an inmate.

Massachusetts Department of Correction spokeswoman Diane Wiffin says the prisoner attacked 2 of the officers with a homemade weapon on Wednesday night after being released from his cell for "tier time," when inmates can participate in recreational activities.

Wiffin said two other officers were hurt while the inmate was being removed from the housing unit. She would not comment on the weapon or the nature of the injuries, but said all four officers were released after treatment at a hospital.

The inmate was not identified.

Wiffin said only the unit where the incident occurred is in lockdown and the rest of the prison is operating normally.

Copyright 2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.