PITTSBURGH (AP) – Pittsburgh police say three people are dead and four others are hospitalized in what they believe to be a mass drug overdose.

Police said Sunday the victims appear to have taken narcotics at the same time and in the same location at a private residence on the city’s South Side.

Authorities say they’re concerned about a “tainted, potentially deadly batch of drugs in the community.”

Five of the victims were found in an apartment, one in an elevator outside the apartment and one on the street. The conditions of the hospitalized victims are listed as serious to critical.

All of the victims were wearing orange paper bands on their wrists. Police determined the victims initially went to a venue together, then headed to the home where they overdosed.