(Reuters) – Apple Inc uncovered fewer cases of child labor than a year ago in its annual survey of the international supply chain that makes parts for its iPhones and iPads. In its eighth annual supply-chain report, Apple also said the metal tantalum, an essential component in many electronic products, had not been sourced from war zones. Apple, the world’s most valuable technology company, has been accused by labor rights groups of building profits on the back of poorly treated and underpaid workers in Asia. (http://link.reuters.com/fac86v) Apple’s latest audit found 23 underage workers at companies supplying it with components.