The Portland Fire Department has temporarily taken its Munjoy Hill-based ambulance out of service to cut costs.

A makeshift sign outside the ambulance bay of Munjoy Station at 134 Congress St. on Thursday read, “Closed. Per city gov’t.”

Deputy Fire Chief John Everett confirmed that the ambulance was taken out of service Wednesday as a cost-cutting measure and would be idle temporarily but indefinitely.

“It’s not a permanent thing,” he said. “But because of our staffing levels, we’re shifting people to reduce our overtime. That means not every ambulance can be manned.”

The Munjoy Station ambulance was picked, Everett said, because it was the least likely to get a high volume of calls. He said the Munjoy Station had responded to one fire call as of about 4 p.m. Thursday but an ambulance was not requested or needed.

The next closest ambulance that could serve Munjoy Hill is at Central Fire Station, down Congress Street. There is an ambulance at the North Deering station on Allen Avenue as well.

Firefighters in Portland are also emergency medical technicians or paramedics, and fire trucks are equipped with some live-saving equipment, although not as much as ambulances have.

Diane Russell, a state representative who lives in the Munjoy Hill neighborhood, said she saw the sign Thursday morning and wondered what had happened.

“I’m not going to criticize the city because I don’t know all the details, but Munjoy Hill is a densely populated neighborhood and we have a lot of elderly residents that live here,” she said. “I’m deeply concerned that we could be losing that ambulance service, even if it’s just temporarily.”

The Portland Fire Department has long dealt with high overtime costs, an issue that has drawn the attention of some city councilors, particularly at budget time.

In 2013, a consultant advised the city to hire more full-time firefighters to reduce overtime spending, but not everyone was satisfied with that recommendation. Portland already has more firefighters per capita that any other medium-sized city in New England, according to an analysis by the Portland Press Herald.