WINFIELD, Mo. (AP) — Mexican drug smugglers are increasingly peddling a form of ultra-potent heroin that sells for as little as $10 a bag and is so pure it can kill unsuspecting users instantly, sometimes before they even remove the syringe from their veins.

An Associated Press review of drug overdose data shows that so-called “black tar” heroin – named for its dark, gooey consistency – and other forms of the drug are contributing to a spike in overdose deaths across the nation and attracting a new generation of users who are caught off guard by its potency.

“We found people who snorted it lying face-down with the straw lying next to them,” said Patrick O’Neil, coroner in suburban Chicago’s Will County, where annual heroin deaths have nearly tripled – from 10 to 29 – since 2006. “It’s so potent that we occasionally find the needle in the arm at the death scene.”

Authorities are concerned that the potency and price of the heroin from Mexico and Colombia could widen the drug’s appeal, just as crack did for cocaine decades ago.

The Latin American heroin comes in the form of black tar or brown powder, and it has proven especially popular in rural and suburban areas.