A woman has been charged after allegedly sabotaging two major Sydney hospitals by cutting gas and water lines.

Vanessa Joy Moulton, 42, allegedly disrupted the critical gas and water supplies at Kareena Private Hospital and Sutherland Hospital, in Sydney's south, during the early hours of Tuesday. 

Police rushed to Kareena Road in Caringbah, 24km south of the CBD, about 4.20am  following reports of vandalism at the two hospitals, which are on the same street. 

Moulton allegedly cut the gas and water mains just after midnight before setting off the fire hoses at one of the hospitals. 

About an hour later, she allegedly walked across the road and switched off the gas main at the other facility.

Sutherland Hospital was forced to switch to portable oxygen and air for two hours after it lost gas supplies at 2am.

NSW Police later arrested Moulton on Parkside Avenue, in Miranda, at about 4am for breach of bail. 

She was taken to Sutherland Police Station and has since been charged with two counts of public nuisance, two counts of trespassing, sabotage, and destroy or damage property and breach of bail.

Vanessa Joy Moulton, 42, has been charged after allegedly sabotaging two major hospitals

Vanessa Joy Moulton, 42, has been charged after allegedly sabotaging two major hospitals

Moulton allegedly cut the medical gas and water supply at Kareena Private Hospital (pictured) and Sutherland Hospital

Moulton allegedly cut the medical gas and water supply at Kareena Private Hospital (pictured) and Sutherland Hospital

She is due to face court later today

She is due to face court later today

She has also been charged  charged with tamper with fire alarm or fire signalling apparatus, trespass on protected premises in relation to an alleged incident at a Darlinghurst hostel on Monday. 

Moulton was refused bail and is due to face Sutherland Local Court later on Wednesday.

NSW Health Minister Ryan Park said the act of alleged 'sabotage' could have had 'catastrophic' consequences for patients. 

'It is very, very concerning that life-saving medical gases have been [allegedly] sabotaged at the public and private hospitals,' he said. 

Mr Park confirmed on Tuesday that the incident did not impact patient care and that gas and water systems have since returned to normal. 

'Access to gas systems in NSW public hospitals is restricted and we will review the incident to see what improvements can be implemented,' he said. 

NSW Health has been contacted for further comment.  

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