LINDEN - Scrap metal thieves are doing major damage to vacant homes in Linden, authorities say.

Police are urging residents to keep a close watch on vacant homes in their neighborhoods after thieves recently broke into three homes in search of copper piping. They say scrap thieves are often not confronted because neighbors assume they are professional contractors hired to do a job.

Two homes on South Stiles Street were recently vandalized each resulting in about $5,000 in damages. Police say stolen copper is hard to track because scrap yards that pay about $3 a pound for the metal do not ask too many questions.

Police are urging landlords and realtors to make frequent checks on any vacant properties.