Federal authorities have charged six people with running a fentanyl drug ring in Maryland, seizing enough of the deadly drug to kill a million people.

In an indictment unsealed on Wednesday, U.S. Attorney Robert K. Hur announced that four people have been arrested and two are still being sought in connection with the Hagerstown drug bust.

In custody were Lekeith Dion Mitchell, 49; Gary Lee Washington, 38; Joenna Marie Nicewarner, 33; and Lama Junior Jean-Pierre, 36.

Still being sought by authorities are Dustin Ray Stipes, 35, and Nyana Angelina Cheese, 28. All six are charged with conspiracy to distribute fentanyl.

Joenna Marie Nicewarner (left) and Lekeith Dion Mitchell (right) were among the six charged with fentanyl distribution in a federal indictment unsealed on Wednesday

During the investigation, law enforcement seized two kilograms of fentanyl.

Just two milligrams of the synthetic opioid can be fatal, and two kilograms is enough to kill 1 million people - roughly 25 times the population of Hagerstown.

The drug is often cut with heroin or other opioids without drug users' knowledge.

State prosecutors say that there have already been victims of the Maryland drug ring. In September, area resident Tara Chantelle Blackwood died of an overdose after being found unconscious in her vehicle on Interstate 70.

Nicewarner was charged with involuntary manslaughter at the state level in Blackwood's death.

Federal prosecutors say from September through December 2018, Nicewarner and the other defendants conspired to distribute fentanyl in Hagerstown and the surrounding area.

The indictment alleges that Mitchell used his Hagerstown home to manufacture, store, distribute, and use fentanyl.

A fatal dose of fenanyl, just two milligrams, is seen next to a penny in this DEA photo. The drug is often cut with heroin or other drugs unbeknownst to users

According to the indictment, on December 17, 2018, Washington possessed a semi-automatic rifle in furtherance of the drug trafficking, and on February 1, 2019, Mitchell allegedly possessed four loaded firearms.

Washington and Mitchell both have previous felony convictions and are therefore prohibited from possessing firearms and ammunition. Both were charged with the weapons violation.

If convicted, all the defendants except Jean-Pierre face sentence of up to life in prison for the fentanyl distribution conspiracy.

Jean-Pierre faces up to 40 years in prison for the conspiracy.

Currently, Washington, Nicewarner and Mitchell are still detained. Jean-Pierre has been released under supervision of U.S. Pretrial Services.

In 2017, more than 70,200 people died in the U.S. of drug overdoses, an average of more than 192 deaths a day.