BOSTON (AP) – Workers at the Deer Island sewage treatment plant on Boston Harbor discovered a baby’s arm in sewage, and authorities said Wednesday the remains could have come from 21 different communities around Boston.

Suffolk County spokesman David Procopio said the arm found Tuesday was several inches long. The arm has been taken to the medical examiner’s office to determine how old the baby was and when the baby died. Results were still pending Wednesday.

Authorities originally contacted authorities in five communities north of Boston for reports of missing infants.

However, the Massachusetts Water Resources Authority on Wednesday said sewage flow from several additional communities north of Boston was diverted for several hours Tuesday into the line that normally serves only East Boston, Revere, Chelsea, Winthrop and Everett.

“The additional flow from that temporary diversion increases the geographic area from which the sewage carrying the remains may have originated,” Procopio said in a statement.

The communities are: Bedford, Burlington, Wilmington, Reading, Wakefield, Somerville, Belmont, Arlington, Medford, Everett, Malden, Melrose, Winchester, Lexington, Woburn, Stoneham, Cambridge, Chelsea, Revere, Winthrop and East Boston.

The remains could have entered the wastewater system through a toilet, sewer, or catch basin, he said.

The State Police and Suffolk district attorney’s office appealed to people in the 21 communities for information on anyone who was recently pregnant but does not now seem to have a baby.