A woman has been accused of deliberately sabotaging two major hospitals after allegedly tampering with water and gas mains.

The 42-year-old allegedly cut the gas and water mains just after midnight on Tuesday, before setting off the fire hoses at a hospital at Caringbah, in Sydney's south.

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

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

Health Minister Ryan Park said the systems were restored within two hours and added his government would review the incident.

"I want to assure the community there was no impact to patient care and that the system has returned to operating as per normal," he said.

"Access to g

See Full Page