Police said a 26-year-old female prison officer was opening a cell door in the minimum security unit five at 6.17am when a 29-year-old inmate assaulted her by striking her in the sternum. It caused her to fall backwards against a wall. She suffered soreness to the chest and lower back.

A 50-year-old male prison officer came to her assistance but police said the inmate punched him "multiple times" in the side of his face. He sustained a cut below his eye and nose, bruising, swelling to his face and a bleeding nose.

Chief Inspector John Sheehan said police were still investigating and would soon interview the inmate, once Corrections NSW approval was granted.

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A Corrections NSW spokeswoman confirmed the assault.

"The inmate has been placed in segregation and will face external or internal charges after assaulting a prison officer at Goulburn Correctional Centre," she said.

She said the Immediate Action Team responded and the prisoner was directed to lie on the floor where he was handcuffed.

Both officers were taken to hospital as a precaution.

Prison officers Vocational Branch chairman, Nicole Jess, told The Post the Union met with the Department on Wednesday.

The inmate was immediately moved and regressed in classification following the assault.

"He was minimum security and we have had discussions with the Department as to why he had that classification given his mental health issues and history of agression towards other inmates. We do not believe it was an appropriate classification," she said.

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Ms Jess said prison assaults had been increasing around the State. The Branch claimed they were up 40 per cent but Corrections NSW has disputed this figure.

However the union is standing by its figures, saying it contacts officers after the assaults for information.

"There is ongoing concern about assaults on officers and we are talking to the Department about getting more detailed information," she said.

The POVB has campaigned for several years on the issue.

In March, prison officers walked off the job in protest over inmate assaults on their numbers, including several in Supermax.

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