Two days after violence broke out at a factory near Bengaluru that produces Apple's iPhone, the US firm has said it is probing if its Taiwanese contractor Wistron Corp, which owns the factory, broke supplier guidelines. "Apple is dedicated to ensuring everyone in our supply chain is treated with dignity and respect. We have teams on the ground and immediately launched a detailed investigation at Wistron's Narasapura facility in India," a company source told NDTV.