SALEM, N.H. (AP) — Police in Salem, New Hampshire, are warning of a particularly deadly batch of heroin/fentanyl after responding to three overdoses in 24 hours, one of them fatal.

Police said they found an unconscious woman in a park and ride area on Thursday morning. They determined she had overdosed. Two hours later, officers went to the same park and ride, where they found a man who suffered an overdose. They treated him at the scene.

Early Friday, police responded to another address to find family members performing CPR on a man who had overdosed. He was pronounced dead at the scene after several attempts to revive him.

Capt. Joel Dolan said all incidents remain under investigation in an attempt to determine where the tainted batch may have originated.