A “safe injection site,” where drug addicts can shoot up using clean needles in Montreal. The sites are one strategy Canada uses to try to counter the high rate of overdose deaths.

PHILADELPHIA — The top federal prosecutor in Philadelphia has filed suit to stop a nonprofit from opening a safe injection site to address the city’s opioid problem.

U.S. Attorney William McSwain says it’s part of an overall plan to target anyone involved in the trafficking or delivery of illegal drugs.

The lawsuit pits McSwain’s views against those of Philadelphia’s mayor, district attorney and a former Pennsylvania governor who support the plan.

McSwain is speaking at a morning news conference as supporters of the planned Safehouse program gather in the lobby of his Independence Mall office, complaining they were barred from attending.

He says he hopes the civil lawsuit filed Tuesday will prompt a federal judge to declare the nonprofit Safehouse program illegal.