(CBS) – An undercover sting known as “Operation Sweet Dreams” and spurred by fentanyl-laced heroin overdoses has netted 65 arrests.

Federal agents and the Chicago Police Department seized guns, money and large quantities of fentanyl-tainted heroin, a deadly drug cocktail.

U.S. Attorney Zachary Fardon and officials from the Cook County State’s Attorney’s Office and CPD say they hope the arrests make a dent in the drug trade.

“Opioids are killing more people nationally than gun violence,” Fardon said during a Thursday news conference.

Fentanyl-laced heroin made up a big part of this latest bust. Fardon says it only takes a trace of fentanyl – 2 milligrams – to kill someone.

For perspective, a sugar packet contains 1,000 milligrams of sugar.

2 Investigators last year showed how drug cartels and gangs were manufacturing cheap fentanyl to mix into heroin to increase their profit margins.

One offender targeted in this drug sweep on Chicago’s West Side is still on the run. Some offenders are charged in federal court, others in state court.

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