SPRINGFIELD - Illinois' largest maximum-security prison is on lockdown status after two fights between inmates and the Saturday discovery of an illegal weapon.

The nearly 3,500 inmates of Menard Correctional Center in Chester have been locked in their cells since Monday pending an investigation of the incidents by prison personnel.

Inmates are not allowed out of their cells to eat or see visitors. No timetable was available for how long the lockdown will last.

The situation at Menard comes as the union representing prison guards is fighting Gov. Rod Blagojevich over his plan to close the maximum-security Pontiac Correctional Center.

The American Federation of State, County and Municipal Employees Council 31 says state prisons are already overcrowded and potentially unsafe for workers.

Most Pontiac prisoners will eventually move to an unused prison in Thomson, but the closure has resulted in some prisoners including 40 from Menard being transferred to other facilities to accommodate the system-wide changes.

Illinois Department of Corrections spokesman Derek Schnapp said the on-going closing of Pontiac is not related to the recent spike in violence at Menard.

But, Schnapp acknowledged prisons through Illinois are in a state of tension because of the fallout from closing Pontiac.

"Right now, I think everything is heightened because of the Pontiac thing," Schnapp said.

Problems at Menard surfaced Friday when two inmates fought during a class. Guards stopped the incident from escalating by firing a warning shot.

On Saturday, while inmates were being moved within the prison, guards found a homemade weapon.

"It looked like a short, four- to five-inch metal piece that was sharpened at one end," Schnapp said.

On Monday, another fight broke out between two prisoners in the dining room. The two cell mates were pulled apart by guards after a warning shot was fired.

At that point, prison officials ordered the facility to be placed on lockdown status.

Menard, located along the Mississippi River in Randolph County, is among five maximum-security prisons in the state. Others include Pontiac, Tamms, Stateville and the all-female Dwight Correctional Center.

kurt.erickson@lee.net|789-0865