New Delhi [India], August 9 (ANI): Union Defence Minister Rajnath Singh on Sunday hailed the blood donors at the 'Sindoor-Army Maha Blood Donation Yatra', saying that donating blood for the Army personnel on the borders is the 'greatest service to the nation'. Addressing a gathering at the 'Sindoor - Army Maha-Blood Donation Yatra (Year 2)' campaign programme at Base Hospital, Delhi Cantonment, the Union Defence