A massive search operation is underway for Indian Air Force AN-32 plane that went missing over the Bay of Bengal on Friday. Defence Minister Manohar Parrikar was overseeing the aerial search operation Saturday for the aircraft.

The plane went off radar when it was heading to Port Blair, the capital city of the Andaman and Nicobar Islands, after taking off from Chennai, the capital of the southern Indian state of Tamil Nadu. The aircraft was reportedly on courier duty. It took a left turn with rapid loss of height from 23,000 feet.

Sixteen ships, a submarine and six planes are involved in the search operation. Two high-tech naval surveillance planes, four other naval and coast guard planes have also been deployed to find the plane. No wreckage has been located yet.

“We are on full force to locate the missing aircraft that went missing yesterday morning. We have got ships, aircraft and submarine deployed there. We are searching. We have not been located anything as yet but the search is on,” Rear Admiral Alok Bhatnagar, Flag Officer of Tamil Nadu and Puducherry Area, told a press conference.

The Russian-made AN-32 can fly for four hours without refueling, Ministry of Defence spokesman Nitin Wakankar said.

According to military authorities, the monsoon caused rough weather conditions in the Bay of Bengal past two days. Air force spokesman Anupam Banerjee said that the last communication from the aircraft was about 15 minutes post-takeoff.

“There was no emergency communication message received from the plane. There is nothing to suggest what exactly happened,” Banerjee said.

Of the 29 people on board, six were crew members (including three officers), 11 other Indian Air Force workers, two army workers, one coast guard sailor, one navy sailor and eight naval civilians.

The same plane suffered three technical problems in July alone, the Indian Express newspaper reported.