A new and lethal strain of synthetic heroin resulted in five overdose deaths in Minnesota this year, and officials believe another five undetermined deaths will also be linked to the drug.

The five cases are the first confirmed in-state deaths caused by carfentanil, a drug from China that is 100 times more potent than the already dangerous fentanyl. Carfentanil is federally approved to immobilize large animals such as elephants for surgery, and two salt-sized specks of the opioid can cause instant death, a local emergency room doctor said Thursday.

The victims, who ranged in ages from 23 to 43, died in Minneapolis, Apple Valley and Faribault in January and February. It appears they had no clue their heroin purchase was laced with carfentanil, and the drug can’t be diluted enough for safe human consumption.

“The drug is so new very little is known about it and the impact the drug has on humans,” said Dr. Jon Cole, an emergency room doctor and medical director of the Minnesota Poison Control System. “We don’t even know how much carfentanil is in the current heroin supply.”

For the past several years, law enforcement has struggled to prevent heroin and fentanyl overdoses. In Hennepin County alone, there were a record 144 opioid-related deaths in 2016. It’s possible carfentanil played a role in some of the deaths, but the drug is so new that testing for it wouldn’t have been required.

“A few years ago no one had heard of fentanyl, but now it is a major factor in the opioid epidemic, and today we learned that an even deadlier opioid [carfentanil] has made its way to our community,” said Hennepin County Sheriff Rich Stanek.

Carfentanil stops a person’s ability to breathe. Beyond Minnesota, other states are getting their first experience with the drug. In New York City this week, 34 people were charged with running a sprawling drug ring that sold a drug very similar to carfentanil. The drug sold for as little as $7 to $10 per dose, and police said it was distributed by a well-known local street gang.

On Wednesday, President Donald Trump announced his plan to create a national effort to combat the opioid crisis that will be led by Gov. Chris Christie of New Jersey.

Locally, many police departments have started education campaigns and prescription-pill disposal centers. They also have trained officers to carry naloxone, a drug administrated through the nose that can revive a person suffering a heroin overdose. If reached in time, the drug can save a carfentanil user, said Cole.

“Prevention is critical,” he said. “We need to be concerned.”

The five carfentanil deaths happened between Jan. 30 and Feb. 17. Three of the deaths were in Minneapolis, and Deputy Police Chief Bruce Folkens said investigators haven’t determined if there are any similarities or the source of the drug.

The cause of the last carfentanil death wasn’t confirmed until two days ago, said Andrew Baker, the chief medical examiner for Hennepin, Dakota and Scott counties. The drug is extremely difficult to detect and few labs can test for it, he said.

When the cluster of carfentanil overdoses was discovered, Baker’s office notified law enforcement, hospitals and poison control centers. Even contact with the smallest dosage of the drug can be dangerous for first responders, he said. The state Bureau of Criminal Apprehension gives naloxone to its agents when they handle search warrants and keep doses near lab scientists.

As part of Gov. Mark Dayton’s proposed budget, the BCA hopes to receive funding for several additional analysts, said agency Superintendent Drew Evans. Last year, his agency did testing for more than 28,000 drug cases, a 47 percent increase from 2015, he said.

Eleven of the cases tested positive for carfentanil, and the BCA has already received a significant amount of requests for fentanyl cases this year.

“This is a health crisis,” said Evans. “Carfentanil will kill you.”

Drew and Apple Valley Police Chief Jon Rechtzigel warned the public and opioid users of the dangers of carfentanil. The chief stressed that overdosing from this drug isn’t just an inner city problem.

Investigators are working locally and nationally to find the source of the carfentanil, said Ken Solek, assistant special agent in charge of the Drug Enforcement Administration’s Twin Cities office. It most likely is made in China and brought in by Mexican drug cartels for distribution on the streets. It could also be bought online, he said.

Since such a small amount is laced in the drug, the profit margin can be high, said Solek. But most intelligence we have is that people don’t even know they are taking it, he said.

“There aren’t a lot of repeat offenders with the drug,” he said. “Any new drug on the market is frustrating for law enforcement. We feel like we are always chasing that dragon.”