Vietnam’s Civil Aviation Authority said on Sunday that a navy plane had spotted an object in the Gulf of Thailand believed to be part of the Malaysia Airlines jet that has been missing for more than two days. However, authorities have not found any debris from the Boeing 777-200, according to NBC News. “This is an unprecedented mystery,” the director of Malaysia’s Department of Civil Aviation said at a news conference. He also said that reports of an object that looked like part of a tail turned out to be something else. The jet went missing early Saturday morning on a flight from Kuala Lumpur to Beijing with 239 people on board.