Thirteen vacant houses sustained major damage Wednesday morning when a suspicious fire tore through them in Shenandoah Borough, Schuylkill County.

According to state police in Schuylkill Haven, the fire started in the rear of 9 N. Union St., and the cause is listed as “incendiary in nature.”Police are asking that anyone with information about the fire contact the state police at 570-739-1330 or the Shenandoah Police Department at 570-462-1991.The fire is being investigated by Trooper Joseph Hall of Troop L – Fire Marshal Unit. Arson is being considered as the reason for the fire.The houses with major damage include: 3, 5, 7, 9, 11, 13, 15 and 17 N. Union St.; 401 Centre St.; and 406, 408, 410 and 412 E. Mount Vernon St. According to the police report, the units are owned by Mary Dumblesky.Julian’s Car Wash on East Centre Street was also damaged by the fire. It sustained minor damage due to heat from the fire, police said.Firefighters from Shenandoah and surrounding communities responded to the scene around 10:40 a.m. and extinguished the fire. An officer at the Shenandoah police station did not have any additional information and Trooper Hall was not available for comment.