Immigration holding facilities in Laval and Vancouver, will be replaced as part of a $138-million overhaul intended to improve detention conditions for newcomers to Canada.

The federal government will also move ahead with plans to expand the range of alternatives to locking up immigrants, with the aim of making detention a last resort, said Public Safety Minister Ralph Goodale.

In addition, a community supervision program will be developed for released detainees.

Goodale announced the details Monday during a visit to the aging Laval facility.

The Canada Border Services Agency holds people who are considered a flight risk or a danger to the public and those whose identities cannot be confirmed.

The Canadian Red Cross Society has found numerous shortcomings at facilities for immigrant detainees, including overcrowding and lack of mental health care.

Newcomers are often held in provincial jails or police facilities alongside suspected gang members and violent offenders.

There are three federal immigration holding centres and the government has flagged the Vancouver and Laval facilities as most in need of attention. One in Toronto is considered to be in better shape.

The planned improvements are designed to reduce reliance on provincial facilities. Some of the new money will go to mental health and medical services for detainees in federal holding centres.

Beginning this summer, the government will hold consultations on increasing the alternatives to detention -- such as electronic monitoring -- and reducing the number of minors behind bars.

Currently, "there aren't enough other choices to make," Goodale said.

Paul Clarke, director of advocacy group Action Refugies Montreal, had sharp criticism for the current state of the centres.

"Here in Montreal, the type of building is like a prison, there are guards everywhere," he said. "Everybody is awakened at 6:00 a.m., everybody eats at the same time. If you have medical needs, there is a nurse and a doctor sometimes on hand, but if you really need to see a doctor outside, you are shackled, you're put in handcuffs and brought in a van to a hospital. In terms of healthcare, it is really not first class."

The Red Cross said the border agency detained 10,088 immigrants -- almost one-fifth of them refugee claimants -- in 2013-14 in a variety of facilities, including federal holding centres and provincial and municipal jails.

Among these were at least 197 minors, held an average of about 10 days each.

However, the number of young detainees was almost certainly higher because the figures did not include those who were not formally part of a detention order, but nonetheless found themselves behind bars with a parent or guardian.