CHICAGO (CBS) — Cocaine laced with fentanyl is suspected in two more deaths in Will county; that makes five since Sunday.

Police said they discovered white powder residue near a man found dead around 8:30 p.m. Wednesday in a home near Notre Dame and St. Jude avenues.

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A similar residue was discovered near another man who died in a Joliet hotel room.

Police said they suspect both men died of an overdose. The Will County Coroner’s office was scheduled to perform autopsies on both men to determine the exact cause of death.

Police suspect dealers are cutting cocaine with cheaper fentanyl, which is more dangerous. It’s a synthetic opioid up to 100 times stronger than morphine.

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Three other deaths and three additional overdoses are suspected to be the result of cocaine mixed with Fentanyl.

On Sunday morning, police found two men who had apparently overdosed at a home near Landau and Elwood avenues. A 40-year-old man died, but officers were able to revive a 35-year-old man, who was taken to Silver Cross Hospital for treatment.

Two days later, police found four people not breathing at a home near Bridge and Center streets. A 39-year-old woman and a 29-year-old man died after they were taken to the hospital. A 28-year-old man and a 30-year-old man were in critical condition.

“When people use illegal narcotics, they never know what is truly in them. Unfortunately this can lead to people overdosing on potentially fatal substances. We want to let the public know we are fully investigating these cases. We also want to make the public aware that it appears Cocaine is now being mixed with Fentanyl. I encourage anyone dealing with addiction issues to please seek help,” Joliet Police Chief Al Roechner said.

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Joliet police are trying to find the source where the fentanyl-laced cocaine came from, in an effort to prevent the supplier from pumping even more drugs into the community.