A federal grand jury has indicted a south Minneapolis man on drug trafficking charges, the latest action in an intensifying campaign against gangs and dealers peddling fentanyl-laced pills on city streets.

The defendant, Mohamed Salah Hussein, "conspired with others to manufacture and distribute large amounts" of so-called "Mbox pills," a spokeswoman for the U.S. Attorney's Office said in a news release. Hussein, nicknamed "Cheese," was originally charged by complaint in February.

He is being held at the Sherburne County jail pending trial.

The release said that the investigation — by the Bureau of Alcohol, Tobacco Firearms and Explosives, the Drug Enforcement Administration, Minneapolis police and the Hennepin County Sheriff's Office — culminated in Hussein's arrest on Feb. 11 when law enforcement officers burst into his Lyndale neighborhood townhouse to serve a warrant. A search of the home turned up $31,285 in cash and about 1,000 fentanyl pills stuffed inside a winter jacket, authorities said. He was charged two days later.

Previously filed court documents say that investigators were first tipped off to Hussein's alleged activities last year by an informant, who claimed that Hussein was manufacturing the drugs using a pill press and selling them out of his black Toyota Camry, often posting up in a fast-food restaurant parking lot in the 200 block of W. Lake Street, around the corner from his house.

The documents say that authorities installed a tracking device on the Camry and later intercepted a FedEx package containing almost 2 pounds of the pills that was believed to be intended for Hussein. Investigators believe that he had been receiving such shipments since at least last June.

When reached for comment Tuesday, Hussein's attorney said the indictment made allegations of "Mr. Hussein's involvement that are incorrect."

"I am confident the evidence will paint a much different picture of Mr. Hussein once it is brought to light," said the attorney, Kevin DeVore, in an e-mail.

In another recent Mbox case, suspected dealer Demarlo Hudson was federally indicted on charges that he oversaw a large-scale counterfeit prescription pill and marijuana operation, which was partly run out of Hudson's music studio in New Hope, authorities say.

Authorities say the pills are made to resemble real oxycodone or Percocet pills but are actually laced with fentanyl, a synthetic opioid that is at least 50 times stronger than heroin and responsible for thousands of deaths nationwide every year.

Named for their signature imprint and also referred to as "blue percs" or "Oxy-30," the counterfeit pills first appeared on local law enforcement's radar last spring, when they were blamed for large spikes in overdoses, including a nine-day stretch in June 2019 during which 65 people overdosed.

Over the ensuing months, local and federal authorities have launched several large investigations targeting the South Side gangs that have virtually cornered the market on Mbox pills.

After one large bust earlier this year, Minneapolis went at least 30 days without an Mbox overdose, officials say. But, they say, the pills have since made a comeback on city streets, where they are sold for about $35 a piece.

Fentanyl can be prescribed legally, often coming in the form of a patch, and has been used for years as an anesthetic and for severe pain relief. Because of its potency, many versions of the drug are outlawed in the U.S., but authorities say that regulation is difficult because manufacturers are constantly tweaking the recipes of their drugs to skirt existing laws.