Extensive damage from a fire at Tata Group's Apple iPhone component plant in southern India could hamper production ahead of a festive season sales surge, an industry watcher and a source said, forcing the U.S. firm's suppliers to arrange critical parts from China or elsewhere. The weekend blaze has caused an indefinite production halt at Tata's Hosur plant in Tamil Nadu, the only Indian supplier of iPhone back panels and some other parts for both contract manufacturer Foxconn in the country and its own iPhone assembly at another plant.