BILLINGS, Mont. (AP) — A Billings man has been charged with felony assault on a minor over a spanking of his 2-year-old son.

Prosecutors say 25-year-old Troy Robin Anthony Villa inflicted serious injury on his son. The Billings Gazette reports a judge on Thursday set his bond at $15,000.

According to court records, the boy's mother told police in October that she found significant bruising on her son's buttocks after picking him up from a visit to his father. The boy said his father hit him, but Villa allegedly said the boy had fallen off a horse.

Villa is scheduled to be arraigned June 8.

He has an unlisted phone number and couldn't be reached for comment.