The death toll in an explosion in a scrap shop in Ludhiana has increased to three. Five others are seriously injured in the blast this afternoon. The injured have been admitted to hospitals.Commissioner of Police, Ludhiana, Ishwar Singh told AIR that all those died and injured were shop workers. The scrap shop was dealing in ordinance scrap also.Police sources suggest that the explosion seems to have been triggered from some old shell.Police have registered a case against the shop owner and investigations are on.