A military plane with 38 people onboard has disappeared on its way to Antarctica, Chile's air force has confirmed.
Radio contact was lost with the plane on Monday evening as it flew to a military base.
Chile's air force has declared an alert and sent out search and rescue teams.
The C-130 Hercules was carrying 17 crew members and 21 passengers, including three civilians. The personnel were to check on a floating fuel supply line and other equipment at the Chilean base.
President Sebastian Pinera said on Twitter that he was "dismayed" and was with his defence and interior ministers at the air force headquarters monitoring developments.
The plane took off at 4.55pm from the southern city of Punta Arenas, which is more than 3,000 kilometres (1,860 miles) from the capital of Santiago. Contact was lost at 6.13pm.
General Eduardo Mosqueira of the Fourth Air Brigade told local media that a search was underway and a ship was in the area where the plane should have been when contact was lost.
General Mosqueira said the aircraft would have been about halfway to the Presidente Eduardo Frei Montalva base, on King George Island, when it lost contact. No emergency signals had been activated, he said.
He said the plane, whose pilot had extensive experience, had been scheduled to return on Monday night.