The Oromocto Public Hospital is shutting down its emergency room and cancelling X-rays and day surgeries on Thursday after a water main break on Wednesday night.

The water problem started in a utility room where the hospital stores its sterilized equipment. Soon after, water flooded the medical and surgical units, leaking through the ceiling into the emergency room.

Officials say staff reacted quickly, moving almost 28 patients from the main floor where the flood happened.

Nicole Tupper, the executive director of the Dr. Everett Chalmers Hospital in Fredericton, said a number of options are open for anyone who needs to see a doctor.

Tupper said the hospital, which is about 20 kilometres from Fredericton, has a contingency plan that sends emergency patients to the capital city's hospital.

"We're asking patients if they have a true emergency to dial 911 as we would expect them to do at any other time," Tupper said.

"Otherwise they can, if it's a non-urgent situation, to see their family doctors, to use the after-hours clinics if possible and if there's no other alternative to proceed to the emergency room at the Dr. Everett Chalmers Hospital."

Fire officials say the unaffected areas of the hospital remain safe for patients and staff.

Tupper said electricians and inspectors were checking electrical systems on Thursday morning to make sure they're safe before being put back into operation.

It is expected that day surgery could re-open as soon as Monday and lab services may be open again on Friday.

The cause of the water main break is still being investigated.