SIBLEY, Iowa (AP) – Authorities say they’re searching for the person who dumped a bag of dead puppies near a northwestern Iowa bridge. The Osceola County Sheriff’s Office says the bag was located near a bridge north of Sibley, Iowa on Northwest Boulevard. The sheriff’s office received a report of the puppies April 6.

The Sioux City Journal reports that the puppies have been described as medium or large breed dogs. Officials say they were seemingly left near the bridge sometime in the winter. The case remains under investigation.