READING, Pa. - The Berks County district attorney has issued a public health alert after a rash of overdoses, some deadly, over the weekend.

District Attorney John Adams said a total of 12 overdoses were reported on Saturday and Sunday in Reading, West Reading, Exeter Township and Rockland Township. Three of them were fatal.

Detectives from several police departments are investigating the incidents.

The substance involved is believed to be cocaine powder laced with an opioid, possibly fentanyl, Adams said in a news release.

The substances were packaged in clear plastic packets or baggies.

"It is critical that the community remain vigilant and check on family and friends who may be using these dangerous drugs," Adams said.

Detectives said they are waiting for toxicology results from medical personnel.

Anyone with information that could help investigators is asked to contact the police or Crime Alert Berks County.

Crime Alert Berks County text-a-tip