NSW inmate 'punctured' in prison assault

A maximum-security prisoner has been admitted to hospital after being assaulted at a correctional facility in NSW.

Emergency services were called to the Mid North Coast Correctional Centre in Aldavilla on Monday afternoon following reports a man had been assaulted.

The 31-year-old male inmate suffered five puncture wounds to his eyebrow, chest, left shoulder and back, a NSW Ambulance spokesman told AAP.

The prisoner is believed to be suffering from a collapsed lung, a Corrective Services NSW spokeswoman said in a statement.

He was taken to Port Macquarie Base Hospital in a stable condition.

Three other inmates - aged 27, 28 and 35 - were identified as "persons of interest".