Residents of a Montauk condo complex are walking on eggshells after they were told there could be World War II explosives on their property.

Montauk Shores is 3 miles from a former Army site called Camp Hero. During the war, Camp Hero was a coastal defense site disguised as a fishing village. Its location was important to prevent an invasion.

The letter from the U.S. Army Corps of Engineers warned residents "military munitions may be present on or near your property."

The pamphlet given to residents shows most of the area of concern is in the Atlantic off the condo's shoreline, an area where Army members at one time may have left behind some weapons of the war.

The letter urges residents to practice the three R’s if they find something: recognize, retreat and report.