LINCOLN — Work is under way again on a water project in the Maine town of Lincoln after contractors determined three 168-year-old headstones found buried beneath the property dig not mark graves.

On Monday workers replacing an 87-year-old water line found the headstones about six feet below the pavement.

Work immediately stopped while officials tried to determine what to do.

Town Clerk Shelley Crosby and others determined the people named on the headstones — all members of the Roberts family — were buried beneath a large family monument in a town cemetery. She tells the Bangor Daily News it’s likely the headstones were given to the family after the larger monument was built.

Work on the water line resumed on Tuesday.