An Indian Air Force transport plane with 29 personnel on board went missing over the Bay of Bengal Friday and a search was launched, officials said.
The Antonov-32 aircraft had taken off from the southern city of Chennai in the morning and was heading for Port Blair in the Andaman and Nicobar Islands.
The aircraft departed around 8:30 am (0300 GMT) and was to have landed some three hours later, air force spokesman Anupam Banerjee said.
Officials said the last contact with the plane was around 15 minutes after take-off.
A search operation was launched by the Indian Navy, Air Force and the Coast Guard around the island group, located some 1,200 kilometres off the Indian mainland in the Bay of Bengal.
Navy spokesman DK Sharma said five maritime reconnaissance aircraft and an equal number of ships were deployed to carry out search and rescue operations.
"A very, very unfortunate news is coming out that one of our aircraft bound for Port Blair, has not reached there yet. It is missing. We will term it overdue," he said.
"The Navy has launched full-scale SAR (search and rescue mission). We hope for the best".
The aircraft can fly for up to four hours without refuelling. They have an emergency beacon locator, which usually gets activated if the aircraft crashes, broadcaster NDTV reported.
Antonov transports have been a mainstay of the Indian military. The Indian Air Force operates 100 of the planes.