PORTLAND – A Coast Guard boat and helicopter are searching Casco Bay after a “mayday” call was broadcast.

Ken Stuart, a search-and-rescue specialist, said the call was broadcast over channel 16, which is the international channel for distress calls, around 8:15 p.m.

Stuart said the call didn’t provide any details, such as the name of the craft in distress or a location. The Coast Guard was able to narrow the area down to Casco Bay by using bearings from the radio signal.

He said the search is going on near Little Chebeague Island. A small boat from South Portland was dispatched and the helicopter was called in from Cape Cod, Stuart said.