Some staff and patients at Calvary Hospital in Bruce were evacuated because of a small electrical fire in a roof cavity in the operating theatre complex of the Xavier Building, also known as Building 4.

An image provided by a patient showed people waiting outside, some sitting on chairs while wearing gowns and attached to IV drips.

The fire started about 12.30pm and activated an internal fire sprinkler system, Calvary said.

Calvary previously advised that no one attend their emergency department unless in an "extreme health emergency", before resuming normal operation on Wednesday.

The theatre complex remained closed on Wednesday afternoon, and Calvary Maternity Services was still on bypass to the Centenary Hospital for Women and Children.

Elective surgery patients affected will be contact, ACT Health said, with alternative arrangements being planned.

An Aranda resident told The Canberra Times she was in the emergency ward when patients and staff were evacuated.

"When the fire alarm sounded, we were evacuated from the emergency section, even everyone in the beds as well as the people waiting outside in the chairs," she said.

"The people in the beds were evacuated into the ambulance bay."

MORE HEALTH:

The ESA said it was notified of the fire at 12.48pm Tuesday.

ACT Health said on social media while the emergency department was open, it asks "that you only attend if your need for care [is urgent]".

"There are other options for less urgent care."

This includes your GP, a Walk-in Centre and the Canberra After Hours Locum Medical Services on 1300 422 567.

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