Foxconn Technology Group has asked hundreds of Chinese engineers and technicians to return home from its iPhone factories in India, dealing a blow to Apple Inc.’s manufacturing push in the South Asian country.

Foxconn, a key manufacturing partner to Apple, has in its bid to diversify its supply chain beyond China, recalled over 300 Chinese engineers and technicians from its India assembly plants over the past two months.

Apple wants to manufacture up to 30 percent of all iPhones in India, but needs Chinese specialists to set up production. But they are now leaving.