An explosion at a Murphin Oil drilling rig caused injuries to workers, said Wallace County Sheriff Larry Townsend on Monday evening. The explosion occurred between 7 and 8 a.m. Monday, southwest of Sharon Springs. Firefighters from Wallace, Weskan and Sharon Springs responded to the incident. Townsend said firefighters were on the scene when he arrived, but he was called away to another incident. He had no additional information.