ST. PAUL, Minn. (AP) - State public safety officials say a batch of heroin possibly laced with other narcotics has apparently caused at least seven overdose deaths in Minnesota in recent weeks.

Investigators believe the heroin also is responsible for more than a dozen non-fatal overdoses.

Law enforcement agencies report suspected heroin overdoses in nearly a dozen north-central Minnesota communities, including Hibbing, Virginia, Bemidji, Detroit Lakes and Dilworth.

The state Bureau of Criminal Apprehension is working to try and identify the source of the drugs.

BCA Special Agent in Charge Sue Burggraf says whether the drugs are coming from a single, potent batch of heroin or different sources, "these drugs are lethal."

Narcotics agents report a big jump in heroin seizures and sales across Minnesota.