Butler County law enforcement authorities are urging heroin users to beware of a potentially lethal batch of heroin that has hit Butler County.

This week at least two overdose deaths and at least seven near-fatal overdoses have been linked to the same batch of heroin, said county Detective Tim Fennell, who heads the county Drug Task Force.

“Ambulance crews are getting swamped tonight,” Fennell said Friday evening.

He noted that Butler Ambulance Service crews responded to several near-fatal heroin overdoses in one shift earlier in the day.

Those incidents have been reported across the county.

One of those near fatalities Friday night occurred at the Walmart in Butler Township. And another occurred in the 500-block of Eau Claire Street in Butler.

Earlier in the day on Friday there were two other non-fatal overdoses just minutes apart on American Avenue and Walker Avenue in the city.

Fire Chief Nick Ban said the number of overdose calls fluctuates week-to-week in the city.

“Some weeks we won’t have any. Other weeks we have half-a-dozen,” he said.

Ban said the number of calls in Butler the past few days has been higher than average, but isn’t far greater than peaks it has had in the past.

“However, the severity of them has increased,” he said.

Narcan, an opioid-antidote drug, has been used to halt some of the effects of the deadly batch of heroin making the rounds, Fennell said. But in many cases three, four or five doses of Narcan have been needed.

“That tells you these are not regular heroin overdoses,” Fennell said.

Authorities are so concerned about the bad batch, or stronger than normal batch of heroin, that Fennell and county District Attorney Rich Goldinger put out an advisory Friday night warning addicts and nonaddicts about the danger.

“We want to get the word out of what we have been seeing,” Fennell said. “Addicts should know what’s out there.

“And we are warning nonaddicts, ‘Don’t handle these packages or bags. We don’t know how toxic they are.’”

The bags linked to the lethal batch are light blue and have no markings on them.

“This batch seems particularly bad and particularly localized,” Fennell said.

He said bags, full and empty, of the lethal heroin collected by police have been sent to the state police crime lab in Greensburg, Westmoreland County, for analysis.

He did not know if the batch is pure heroin or has been laced with Fentanyl or some other ingredient.

“We don’t know what’s causing the problem,” Fennell said. “But it is bad, and we want to identify the source.”

The Drug Task Force earlier this week arrested nine people accused of selling heroin, crack cocaine and prescription drugs in and around Butler.

Authorities still are seeking six suspected dealers.

Because Narcan is now available to the public under a new state law, there was a seminar on Narcan use training Wednesday at Butler County Community College.

About 90 people heard a representative from Prevention Point Pittsburgh discuss Narcan use.

Anyone with information on the heroin is asked to contact the Drug Task Force at 724-284-5225, the Drug Tip Line at 724-431-2456, or their police department.

Eagle staff writer Will DeShong contributed to this report.