PORTLAND (AP) – The Coast Guard and the Maine Marine Patrol say bells and gongs have been removed from at least seven buoys off the Maine coast, prompting suspicions that they are being stolen and sold.

Coast Guard Chief Warrant Officer Jeffrey Chase says thieves may be selling the metal sound signals to nautical novelty shops or scrap metal yards, where they could fetch hundreds of dollars apiece.

Chase, the aids to navigation officer for northern New England, says intelligence officers are working with local shops and scrap yards to identify missing property.

The Coast Guard says missing navigational aids put mariners in danger.