Geological Survey of India's Samudra Ratnakar, searching for AN-32, has detected objects underwater

Objects found underwater by a specialized ship off the Chennai coast are suspected to be the debris of the Indian Air Force AN 32 plane that vanished last month with 29 on board.The Geological Survey of India's Samudra Ratnakar, armed with special Sonar equipment, spotted what looked like the debris of an aircraft a little after 2 pm on Sunday.The objects have been found at a depth of 3,500 metres and around 200 to 300 nautical miles from Chennai.The Air Force says it is trying to verify if the objects are debris from the missing plane, but it is "too early" to say anything for sure. Another highly specialised vessel, the Sagar Nidhi of the National Institute of Ocean Technology, is also searching the area where the AN-32 was last picked up on radar.Both ships are equipped with multi-beam echo sounders which can profile an object on the sea floor with a resolution of two metres.The ships also have sonar equipment designed to detect objects up to 150 metres beneath the sea bed. If something is detected, remote-controlled rovers from the ships can dive to the sea-floor and physically retrieve parts of the wreckage using their claws.Dornier aircraft of the Coast Guard are also flying over the spot.In what has become India's largest search operation at sea, 17 ships, a submarine and 23 aircraft have been hunting for the plane since it went missing on July 22.The plane did not have an underwater locator system, which has made the search difficult.Last month, Defence Minister Manohar Parrikar told parliament that "all leads had turned out to be bad".