Rescue experts who reached a helicopter that crashed in Peru's Andes said there were no survivors among the 14 people on board, including eight South Koreans and three Europeans.
Raul Aybar, a police commander who went to the crash site, said the aircraft "crashed into the snowy Mama Rosa and exploded".
"Everyone died in the initial impact because everything is burned and scattered," Mr Aybar said after returning to the nearest city, Ocongate.
He said operations at the crash site had been suspended until today because of bad weather and darkness. He said temperatures had dropped to minus-15 Celsius.
Peru's police chief, General Raul Salazar, said earlier that searchers found "some parts of the helicopter that have been scattered up to 200 metres by the force of impact".
Authorities said the crashed Sikorsky S-58ET was found at an attitude of about 16,000 feet.
Police said a Dutchman, a Czech, a Swede, eight Koreans and three Peruvians, including the pilot and co-pilot, were on the helicopter.
Seoul's state-run Korea Water Resources Corporation said its vice president flew to Peru on Friday. A Samsung C&T official said his company also sent a team of workers to Lima.
The South Korean embassy in Lima said its nationals were exploring a potential hydro-electric project near Mazuco.
Separately, four people were killed when their helicopter crashed in southern Germany. Rosenheim police said the civilian helicopter was bound for the Austrian city of Salzburg when it crashed into a forest near a major road on Saturday. The Austrian-registered Robinson R44 helicopter was destroyed in the crash, with some of it bursting into flames. The two women and men aboard died at the crash site.