A plane carrying 38 people, including 21 passengers, has disappeared en route to Antarctica.
The aircraft also carries tourists to the Chilian base in Antarctica.
The C-130 Hercules military plane was flying from Santiago and it had briefly touched down in Punta Arenas in south Chile before continuing on to its destination.
Chile’s air force said the military had declared an alert after radio contact with the aircraft was lost last night.
It has activated search and rescue teams but the Chilean Air Force said it was assuming the plane had crashed.
The personnel were flying to check on a floating fuel supply line and other equipment at the Chilean base.
In addition to crew members and armed forces personnel, the plane was also carrying employees from an engineering firm and from the University of Magallanes.
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.
Mosqueira said the aircraft would have been about halfway to the Antarctic base when it lost contact.
No emergency signals had been activated, he said.