Police in Boulder are now backtracking on their claim that over the weekend a group of University of Colorado students overdosed on cocaine that was possibly tainted with fentanyl.

In an update Tuesday, the Boulder Police Department walked back its claim that University of Colorado Boulder students overdosed on a possibly tainted batch of cocaine over the weekend.

Boulder police said five men were treated at the scene or taken to the hospital, and one of them — whose prognosis initially had been “grave” — remained hospitalized Tuesday.