WILLIMANTIC, Conn. (AP) — Police say they are investigating seven drug overdoses within a 24-hour period in Willimantic.

Four overdoses happened Thursday and three took place on Wednesday. Police say one victim remains in the hospital and the other six have been treated and released.

Authorities say six of the overdoses were from synthetic marijuana. The cause of the seventh overdose wasn't given.

Police Cpl. Stan Parizo, Jr. warns that there are "acute medical complications" associated with the use of synthetic marijuana, an illegal, street-level drug.

Police are urging anyone with information about the use, sale or source of the drug to contact them.