MINNEAPOLIS (WCCO) – Authorities in Anoka County say there were an “alarming” number of heroin overdoses in the area Saturday.

Saturday afternoon the Anoka County Sheriff’s Office said five heroin overdoses occurred in Anoka County or were treated at an Anoka County hospital since 5:30 a.m.

Two of the people who overdosed are dead, two have been revived and one remains in critical condition, authorities said.

“Although it is only speculation at this point,” Cdr. Paul Sommer said, “we are concerned about the possibility of a quantity of heroin that may be the single source of these overdose cases.”

Four men and one woman overdosed, the sheriff’s office said. All of the victims are in their 20s.

A leading drug abuse expert in Minnesota told WCCO heroin deaths are increasing in the state, especially in that age group as the use of painkillers, counterfeit pills and opioids increases.

“Many people think drug abuse doesn’t affect them personally if they don’t have a family member or coworker involved,” Carol Falkowski said, “but drug abuse affects all of our systems. It drives up the cost of law enforcement, of our medical care. It drives up our social services.”

Two of the five people are from Fridley, one is from Anoka, one is from Andover and one is from Isanti, but was treated at a hospital in Coon Rapids.

Just before 6 p.m., Sommer tweeted that a sixth heroin overdose occurred in Ham Lake. The victim survived the overdose, Sommer said.

6 th heroin overdose in Anoka County for the day (all in a 12 hr period) in Ham Lake. Victim survived. — Cdr. Paul Sommer (@PIOAnokaSheriff) October 22, 2016

A great concern right now as the investigation continues is if any more people could overdose if in fact these cases are related to one batch of drugs.

Three people were treated for possible drug overdoses at the Mall of America Friday night, but Bloomington police said they could not confirm if those cases were related to the overdoses in Anoka County.