TORONTO -- More than 100 health groups urged Doug Ford and Ontario's health minister on Thursday to reconsider the province's position on overdose prevention sites, saying a government decision to halt the opening of new facilities was putting lives at risk.

In an open letter, the groups said a recently announced provincial review of the sites was "unnecessary" and a moratorium on opening such facilities was troubling.

"All the available evidence, including substantial peer-reviewed scientific literature, demonstrates conclusively that these health services save lives and promote the health of people who use drugs," the organizations wrote.

"Delays mean more preventable overdose deaths and new infections of HIV, hepatitis C and other illnesses that could be averted."

Earlier this month, the Progressive Conservative government paused the planned openings of several overdose prevention sites and said it was conducting a review to determine if such facilities could continue to operate.

The health minister has said a decision on the sites will be made by the end of September.

Nicholas Caivano, a policy analyst with the Canadian HIV AIDS Legal Network, which spearheaded the letter, said health groups came together to urge the government to work with community organizations and other health services to ensure greater access to overdose prevention sites.

"We are absolutely in the midst of a crisis, we are seeing it every single day, so it is very troubling that we have this delay instead of the scaling up of these sites," he said. "We are not sure why they need additional evidence when it's incredibly clear that these interventions work."

The letter was signed by organizations that include the Canadian Medical Association and the Centre for Addiction and Mental Health.

A spokeswoman for Health Minister Christine Elliott said the province is conducting an "evidence-based review"of overdose prevention sites.

"(The ministry is) listening to experts, community leaders, community members and individuals who have lived through addiction to ensure that any continuation of drug injection sites introduce people into rehabilitation and ensure those struggling with addiction get the help they need," the spokeswoman said in a statement.

"In the interim, the ministry has indicated that no new sites should open to the public."

Premier Doug Ford has called overdose deaths a tragedy and said the government's goal is to save lives, get people off drugs and into rehab.

More than 3,800 people died from opioids in Canada in 2017, compared to 2,978 in 2106, according to the latest figures by Canada's health agency published last June.