PITTSBURGH -- Authorities have released the names of three men who died in an apparent mass drug overdose at a Pittsburgh apartment complex that left four other men hospitalized.

Police say the men initially went to a venue together, then headed to the apartment Sunday where they used narcotics at the same time and in the same place. Authorities haven't specified which drug or combination of drugs they took. They also haven't said where the men went together before returning to use the drugs, although authorities say all the victims were wearing orange paper wrist bands.

The Pittsburgh Department of Public Safety said the overdose deaths were not a case of a tainted drug being distributed in a large volume where it could have affected even more people. It appeared to have been isolated to a single location, but police said they are concerned about a tainted, potentially deadly batch of drugs in the community.

Three men -- 32-year-old Rubiel Clemente-Martinez, of Columbus, Ohio; 38-year-old Josue Soberal Serrano, of Carthage, Mo., and 32-year-old Joel Pecina, 32, of Coraopolis -- were pronounced dead at the scene.

One man remained hospitalized Monday in critical condition, while three others were in stable condition.

Five of the victims were found in an apartment. Clemente-Martinez was found one in an elevator outside the apartment and another person was found on the street, authorities say.

The apartment complex management said the victims were not tenants of the building, but knew someone who lived there.