Nassau County police officials are alerting Long Islanders to a “bad batch” of heroin circulating in the Atlantic City area called King of Death that led to 10 suspected overdoses, six of them fatal, in one day this past week.

A public safety announcement was initially issued by Atlantic City police on Thursday about the overdoses — six fatal and four involving people who were revived using Narcan — that took place between 4 and 10 p.m. Wednesday.

Bags made from folded wax paper that were stamped with a red crown and the words King of Death were found at two scenes and are reportedly responsible for those two deaths, Nassau County police said in a public safety advisory released late Friday.

Nassau County police said its officers are monitoring what it called a “drug outbreak” in Atlantic City. A representative of the Atlantic City police did not immediately return a request for comment Saturday morning.

A Nassau police spokesman said officials are monitoring the situation because of Atlantic City’s proximity to Long Island. Nassau police advise residents to call 911 immediately if they know someone who may be using heroin and experiencing an overdose.

For more information about how to help someone addicted to heroin, visit heroinprevention.com or call 877-846-7369.