Pittsburgh police are investigating after three people died and four were hospitalized following a multiple drug overdoses in South Side early Sunday. Watch the latest report from Pittsburgh's Action News 4 in the video player above. The three dead have been identified as Rubiel Clemente-Martinez, 32, of Columbus; Joel Pecina, 32, of Coraopolis; and Josue Soberal Serrano, 38, of Carthage.Five victims were found inside an apartment. One was found in an elevator and another was found at 26th and Carson streets.Federal charges have been filed against Peter Rene Sanchez Montalvo, also known as Carlos, for the multiple fatal and non-fatal drug overdoses. Montalvo was arrested early Monday morning in McKees Rocks, federal law enforcement officials announced. Montalvo is charged with possession with the intent to distribute and distribution of a controlled substance causing death and serious bodily injury. Police said Montalvo was at the Insomnia Discotec in Brookline on Saturday night, where orange wristbands were distributed to patrons. All of the overdose victims wore orange wristbands. At some point in the evening, Montalvo left Insomnia and went to the South Side apartment where he had been staying. Several other individuals who were at Insomnia, including members of the band that played at the bar Saturday night, joined him for what was described as an "after-party." Police said Montalvo distributed a white powdered substance, believed to be cocaine, to those in attendance. Shortly after, multiple people became seriously ill and three of them died at the scene. The conditions of the victims in the hospital range from serious to critical. Police said they are concerned about a tainted, potentially deadly batch of drugs in the community. "We remind the public not to use drugs. Simply put: You do not know what's in that drug," police said in a news release. Read the statement from City Club Apartments management below: “The individuals that were involved in the incident were not residents of our community. It is our understanding that they were acquaintances of a resident in good standing. It is also our understanding that the group had attended an outside event before returning to the apartment. "We express our deepest sympathies to the families and friends of the affected individuals and send our thoughts and prayers to those who were transported to the hospital."We are working closely with the local authorities. As this is an ongoing police investigation, all questions should be directed to the Pittsburgh Police Department.”