After more than a century-and-a-half of operation, the aging Kingston penitentiary is being shut down, Public Safety Minister Vic Toews said Thursday.

The medium-security Leclerc Institution in Laval, Quebec, will also be shuttered within the next two years, Toews said. Also scheduled for closure is a psychiatric institution housed inside the Kingston Pen, called the Regional Treatment Centre.

The minister said all the facilities are housed in aging buildings with old infrastructures that don't meet the needs of today's prisoners.

"Institutions built in the 19th century are not appropriate for managing a 21st-century inmate population," Toews said. "Simply put, we have better options."

Toews said that his government is able to go ahead with these closures because, contrary to popular belief, his government's tough-on-crime legislation has not significantly increased Canada's prison population. Instead, it's simply kept offenders behind bars longer, he said.

"The influx of new prisoners originally predicted is not materializing," Toews said.

The closures will save $120 million a year, the minister said, adding the government has no intention of building new prisons. Instead, it will move current prisoners to other facilities.

The closures come as part of a round of budget cuts that will see the Conservatives cut spending by about $5.2 billion over the next three years.

Opened in 1835, the Kingston Penitentiary is one of the oldest prisons in continuous use in the world. It is one of nine prisons in the Kingston area and houses between 350 and 400 inmates, plus another 130 inmates at the psychiatric treatment centre inside the prison.

Some of Canada's most notorious convicted murderers are housed there, including Paul Bernardo, Russell Williams and Mohammad Shafia.

The Leclerc Institution opened in 1961 and houses 481 inmates including a number of organized crime figures.

Corrections Canada is the third largest employer in the Kingston Region with more than 4,000 positions. Those include 465 at Kingston Penitentiary, 178 employees at the Regional Treatment Centre, and 358 people employed at Leclerc Institution. Toews said most of those employees will be reassigned to other facilities.

CTV News Channel's Mercedes Stephenson said that up to 1,000 prison guards could be "affected" by the move.

But Kingston Mayor Mark Gerretsen said that Corrections Canada was confident it could find jobs for the employees in other prisons.

"We are under the impression … they are going to be looking to re-locate them within our community," he said.

"Our hope is that no employee and no family is affected by this."

Gerretsen was unsure of the plans for the historic building.

Indeed, the plan also caught the prison guards by surprise as well.

"We are certainly denouncing this type of plan," Jason Godin, Ontario regional president for the Union of Canadian Correctional Officers to CTV News Channel. "We don't feel that it's been looked at closely enough and clearly it is quite a surprise for us."

Catherine Latimer, executive director of the John Howard Society of Canada, a group that advocates for correctional justice policy, says she's worried what will become of the Kingston Penitentiary's current prisoners.

"I think all of us are pleased to see the closure of Kingston Penitentiary, which is a very old and antiquated institution that was probably not fulfilling the corrections dynamic as much as we would like," Latimer told CTV News Channel.

"But the problem that we have is: What are you going to do with the offenders that were in Kingston? They are a very unique group of offenders who will not be easily integrated in the same way into other prisons."

She notes that a lot of Kingston's prisoners were in protective custody and can't be easily moved into other institutions.

"It's troubling to see how this is all going to unfold," Latimer said.

The Millhaven Institution -- the closest maximum security facility to Kingston -- currently has 110 or so more prisoners than it's designed for. The maximum security and special handling unit in Saint-Anne-des-Plaines, Que. is also over capacity by more than 200 inmates.