NEW DELHI, Aug 8 (Reuters) - India in recent months has barred domestic manufacturers of military drones from using components made in China over concerns about security vulnerabilities, according to four defence and industry officials and documents reviewed by Reuters. The measure comes amid tensions between the nuclear-armed neighbours and as New Delhi pursues a military modernisation that envisages greater use of unmanned quadcopters, long-endurance systems and other autonomous platforms. But as the nascent Indian industry looks to meet the military's needs, the defence and industry figures said India's security leaders were worried that intelligence-gathering could be compromised by Chinese-made...