India's first military chief General Bipin Rawat, his wife and 11 other armed forces personnel were killed in a chopper crash in the southern state of Tamil Nadu on Wednesday.

The 63-year-old decorated Chief of Defence Staff (CDS) was on his way to deliver a lecture at the Defence Services Staff College in Wellington when the ill-fated Mi-17 V5 helicopter crashed just before landing around 11.45am in the hilly terrain of the Nilgiris in the state's Coonoor district and burst into flames.

A senior Air Force officer accompanying the four-star General survived the fatal crash but sustained severe burn injuries. He has been identified as Group Capt Varun Singh, who is currently under treatment at the Military Hospital in Wellington.

Read: India's military chief feared dead in chopper crash

"With deep regret, it has now been ascertained that Gen Bipin Rawat, Mrs Madhulika Rawat (wife) and 11 other persons on board have died in the unfortunate accident," the Indian Air Force (IAF) tweeted in the evening after day-long DNA tests confirmed the identities of the bodies, some of which were burned beyond recognition.

"An Inquiry has been ordered to ascertain the cause of the accident," the Air Force said in a tweet earlier in the day, soon after the crash.

Indian President Ram Nath Kovind, the supreme commander of the armed forces, Prime Minister Narendra Modi and his top Cabinet colleagues, and the country's main opposition Congress leader Rahul Gandhi took to Twitter to condole the death of the country's top military officer.

"I am shocked and anguished over the untimely demise of Gen. Bipin Rawat and his wife, Madhulika ji. The nation has lost one of its bravest sons. His four decades of selfless service to the motherland was marked by exceptional gallantry and heroism. My condolences to his family," President Kovind tweeted.

Prime Minister Modi called General Bipin Rawat "an outstanding soldier". "A true patriot, he greatly contributed to modernising our armed forces and security apparatus. His insights and perspectives on strategic matters were exceptional. His passing away has saddened me deeply," he wrote.

Indian Defence Minister Rajnath Singh described the top General's death as an "untimely" and "an irreparable loss to our Armed Forces and the country"."General Rawat had served the country with exceptional courage and diligence. As the first Chief of Defence Staff he had prepared plans for jointness of our Armed Forces," he tweeted.

"I extend my condolences to the family of Gen Bipin Rawat and his wife. This is an unprecedented tragedy and our thoughts are with their family in this difficult time.
Heartfelt condolences also to all others who lost their lives. India stands united in this grief," Gandhi wrote.

General Rawat has had a chequered career in the armed forces spanning over 40 years, rising from the rank of a junior commissioned officer to the Indian Army chief and eventually the first head of the tri-services -- the Army, the Navy, and the Air Force. He reported directly to the Indian Prime Minister.