Police took down a “large-scale heroin-packaging mill” in New York City this week and seized suspected drugs worth an estimated $12 million, authorities said Wednesday.

Monday’s bust in Queens involved a man who was allegedly overseeing the packaging operation and three women accused of working for him, the Drug Enforcement Administration said in a statement.

Around 86 pounds, or 39 kilograms, of what is believed to be heroin and 1,000 suspected fentanyl pills were seized, officials said. Lab tests were pending, the DEA said.

Luis Martinez, who allegedly ran the operation out of his apartment, faces charges of operating as a major trafficker and other counts. He and the three women were arraigned Tuesday night, officials said. It was not immediately clear if they had attorneys.

They were arrested Monday afternoon after Martinez left the apartment while carrying a backpack with $200,000, officials said. Inside the apartment, police found the three women and the drug packaging operation, according to the DEA.

Authorities from several agencies involved said the bust would save lives. Opioid addiction and overdose deaths have been called a nationwide crisis.

“This drug den contained nearly $12 million dollars’ worth of narcotics and was like an opioid landmine capable of dispersing hundreds of thousands of heroin doses throughout Northeast,” Ray Donovan, DEA special agent in charge for New York, said in a statement.

More than 81,000 drug overdose deaths involving drugs of all kinds in the United States were reported between May 2019 and May 2020, which is the highest ever recorded in a 12-month span, the Centers for Disease Control and Prevention said late last year.

The public health agency said that synthetic opioids mostly illicitly made fentanyl appeared to be the primary driver of the increase in deaths.

Fentanyl is a powerful synthetic opioid that is cheaper than heroin and is sometimes mixed with heroin to make it more potent. People can be unaware it has been added, which increases the risk of overdose, experts have said.