Three men died and four others were hospitalized in Pittsburgh early Sunday morning as a result of overdoses, authorities said.

All of the men were wearing orange paper bands on their wrists and had been at the same event at the same venue, police said. The men left the venue, which officials did not identify, to go to a private residence, where they overdosed on drugs together, police said.

“To be clear, this was not a case of a tainted drug being passed around or distributed in large volume at a large venue which could have affected even more people,” Chris Togneri, a spokesman for the Department of Public Safety, said. “It appears to have been isolated to a single location.”

Officials did not identify the drugs that had led to the overdoses. However, in a statement, police said they were concerned about “a tainted, potentially deadly batch of drugs in the community.”

“We remind the public not to use drugs,” the statement said. “Simply put: You do not know what’s in that drug.”

Authorities had received a report at 3:20 a.m. of a man found on the street who required medical help. Nearly an hour later, a second medical call came about a man in the elevator of an apartment building about two blocks away from where the first man had been found, Togneri said.

At about 5:40 a.m., authorities found five men inside an apartment, two of whom were dead. The man found in the elevator also died, he said.

None of the men were tenants at the apartment in the Southside Works City Club Apartment building, said Mark Winter, a spokesman for the building, adding that the men had been visiting a tenant who was “in good standing.”

“It is also our understanding that the group had attended an outside event before returning to the apartment,” Winter said in a statement. “We are working closely with the local authorities.”

Togneri said police identified multiple venues in the city that had used orange wristbands on Saturday night for events and concerts.

“News reports linking this incident to specific venues are incorrect,” he said. “Anyone who attended one of these events has no cause for concern regarding their health.”