Providence, R.I. (AP) — The U.S. Coast Guard is asking parents to educate their children about distress calls after receiving what it believes were four hoax calls by children in Southern New England in the past month.

Most recently, the Coast Guard sent a helicopter and boat to search around Portsmouth, R.I., Saturday evening after a child made a fake "mayday" call. They were joined by boats from the Warwick, Portsmouth and Providence fire departments. The search cost $20,000 and found nothing.

Commander Jeannot Smith says two other such calls have come in from Narragansett Bay and another has come in from near Cape Cod.

Smith says if a parent thinks his child has made a fake distress call, he should call the Coast Guard so they don't waste time on a search.