ALAMEDA — A work crew digging on Washington Street today unearthed human bones that may have been buried since the 1920s, police say.

A representative from the coroner's office told police that the bones — which include ribs and a jaw with teeth — are not Native American.

It's unclear whether the bones came from a man or a woman, Alameda police Lt. Bill Scott said.

The crew from the Public Works Department discovered the remains after they removed about a 10-inch square of concrete as part of digging a "sink hole" in the gutter of the 3000 block of Washington Street.

The workers notified police who notified the coroner.

Investigators suspect the bones may have been buried about 80 years because of a date stamped on a nearby sidewalk, Scott said.

As of this morning, detectives remained at the scene and were awaiting an excavation crew from the coroner's office.

A spokesperson for the Public Works Department was not immediately available for comment.

Reach Peter Hegarty at phegarty@bayareanewsgroup.com or 510-748-1654.