NEW YORK (AP) — New York Mayor Bill de Blasio on Thursday threw his support behind a plan to open supervised injection sites for illegal drug users as part of a pioneering yet controversial effort to combat fatal overdoses.

Dozens of supervised injection sites have opened in Canada, Europe and elsewhere in the past decade, but there are currently none in the U.S., although officials in San Francisco, Philadelphia and Seattle have made moves to open them. The facilities are designed to provide a safe place, away from public areas, where drug users can inject heroin under the watchful eye of medical professionals.

“The opioid epidemic has killed more people in our city than car crashes and homicides combined,” said de Blasio, whose endorsement of the plan comes on the same day the city’s Health Department released a long-awaited study that claimed the program could prevent 130 overdose deaths each year.

Preliminary data shows there were 1,441 overdose deaths in New York City in 2017.

If the plan is approved, Overdose Prevention Centers under a one-year pilot program would open at current needle exchanges in Brooklyn’s Gowanus neighborhood, Manhattan’s Midtown West and Washington Heights, and Longwood in the Bronx. Trained staff would be available to administer naloxone, an overdose-reversing drug, and addiction guidance counseling.

“After a rigorous review of similar efforts across the world, and after careful consideration of public health and safety expert views, we believe overdose prevention centers will save lives and get more New Yorkers into the treatment they need to beat this deadly addiction,” de Blasio, a Democrat, said in a statement.

City officials say the proposed plan would need approval from the state Department of Health, council members representing the sites and an agreement from district attorneys to shield clients and operators from prosecution.

Kassandra Frederique, the New York state director at the Drug Policy Alliance, called it a critical step forward in preventing overdose deaths.

“We know that safer consumption spaces are an evidence-based solution that can help dramatically in saving lives, reducing criminalization, and improving public health,” said Frederique.

Ed Mullins, president of the Sergeants Benevolent Association, attacked the injection facilities plan.

“It’s total insanity,” he said. “Drugs are illegal. So we are now telling people it’s OK to break the law.”