The Antonov An-32 took off from Assam's Jorhat at 12:25 pm.

Highlights Antonov An-32 transport plane was headed for Mechuka in Arunachal

Flight took off at 12:25 pm, was supposed to reach in about 50 minutes

Last contact at 1 pm, extensive search operation launched

An Indian Air Force transport aircraft that took off from Assam's Jorhat with 13 people onboard on Monday has gone missing over over hilly terrain in the Northeast.

The Antonov An-32 took off at 12:27 pm for a remote military landing strip in Mechuka in Arunachal Pradesh.

The aircraft last had contact with ground crew at 1 pm, sources have told NDTV. The normal flight time between Jorhat and Mechuka is about 50 minutes.

The Air Force has launched a search operation and spokesperson Lieutenant Colonel P Khongsai said every effort was being made to locate the missing plane. The Indian Army, Indo-Tibetan Border Police and the state disaster relief force joined the search along with planes and helicopters.

Defence Minister Rajnath Singh tweeted about the incident.

Spoke to Vice Chief of @IAF_MCC, Air Marshal Rakesh Singh Bhadauria regarding the missing IAF AN-32 Aircraft which is overdue for some hours.



He has apprised me of the steps taken by the IAF to find the missing aircraft. I pray for the safety of all passengers on board. - Rajnath Singh (@rajnathsingh) June 3, 2019

With bad weather and difficult terrain impeding the operations, the Indian Air Force said the search would continue on Tuesday.

Some reports of possible location of crash site were received, however, no wreckage has been sighted so far. 3/4 — Indian Air Force (@IAF_MCC) June 3, 2019

Located in a picturesque and sparsely populated valley, Mechuka has one of the many rudimentary landing strips run by the Air Force near the Line of Actual Control with China.

The terrain under the flight's route is mountainous and heavily forested. The landing and take-off approaches to Mechuka are extremely difficult. Coupled with erratic weather, the region is among the most inhospitable for air transport.

"The aircraft may have got entangled in low clouds. Flying in these areas is fraught with a measure of uncertainty," Air Commodore Prashant Dikshit (Retired) told NDTV.

The An-32 is a Soviet-designed twin engine turboprop transport aircraft used extensively by the Indian Air Force for over four decades. Since it joined the IAF fleet, the rugged planes used to ferry people and air-drop supplies have undergone several rounds of upgrades.

In 2016, an Indian Air Force An-32 disappeared while flying over the Bay of Bengal after taking off from Chennai for the Andaman and Nicobar Islands.

The search and rescue operation became India's largest such operation for a missing plane on the sea in history but the aircraft was never found. All 29 people onboard were presumed dead.