CELINA, Ohio. (WOWO): Police in Celina, Ohio are investigating bones that were found near Grand Lake St. Mary's State Park. 

Our partners in news at 21Alive are reporting that investigators believe the bones are human. They're treating the investigation as a homicide. 

There have been no reports of anyone missing in Celina. 

Someone walking in the park found the bones on Sunday. Officers thought they may have been animal bones at first, but they've since changed their mind. 

The search is expected to continue through Thursday.