Northern State Prison is under lockdown as officials investigate an inmate stabbing at the Newark facility.

Corrections Department spokesman Matt Schuman says the male inmate is alert and talking after two other inmates inflicted puncture wounds to his chest Monday morning.

Schuman says the injuries were not life-threatening and the incident was isolated.

It's unclear what kind of weapon was used in the stabbing.

The prison holds more than 2,800 inmates under minimum to maximum security conditions.