ALIQUIPPA, Pa. — Fifteen to 20 dead dogs have been found along the Ohio River near Pittsburgh, and police are investigating it as foul play.

Police Chief Brian Uhrmacher says a man taking a walk discovered the dogs Monday morning. The remains were spread over about 50 yards on a hillside in Hopewell Township.

It’s unclear who left the dogs there or why.

The Beaver County Humane Society has also joined the investigation. They are trying to help find out how the dogs died and see if any had microchips that would identify them or their owners.

Uhrmacher says police aren’t sure how long the dogs had been there, but they were in various states of decay.

Police do not yet know the breeds or ages of the dogs.