A bus carrying tourists from a cruise ship plunged more than 100m into a mountain ravine in northern Chile, killing 12 US citizens and seriously injuring two others, officials said.
The Chilean bus driver and a guide were also injured in Wednesday's accident along a rugged highway near the Pacific port city of Arica, 2,000km north of Santiago.
The identities of the victims were not immediately released.
The tourists were returning to their Bahamas-registered Millennium cruise ship after visiting the nearby Lauca National Park. The driver lost control of the vehicle trying to avoid an oncoming truck that had just rounded a curve, according to Juan Pablo Poli, a spokesman for the city of Arica.
Poli said two Americans were in a serious condition at a local hospital. A third injured American died, raising the death toll to 12.
"We have confirmed that all the victims were American citizens," he said. "Autopsies will be conducted during the night so the bodies can be sent home as soon as possible, probably by air from Santiago."
He said the bus had a capacity of 16 passengers and "was totally destroyed as it fell more than 100m."
The accident took place 42km northeast of Arica on the mountain road connecting the coast with the Bolivian capital of La Paz.
US embassy spokesman John Vance, who also confirmed the 12 US deaths, said the embassy was sending consular officers to Arica.
The Millennium was docked in Arica, and the cruise line said the ship would remain there until further notice. It had been scheduled to leave for Peru early yesterday. The ship was carrying approximately 1,500 guests and 920 crew.
The cruise line said it was flying family members of victims to Chile and sending a special assistance team to the ship to help its guests and crew.
"We continue to work with Chilean authorities and the US consulate in Santiago to assist our injured guests and the family members of those who died in this tragic accident," said Dan Hanrahan, president of Celebrity Cruises.
The ship is on a 14-night South American cruise. It departed Valparaiso, Chile, on Sunday and is scheduled to conclude in Fort Lauderdale, Florida, on April 2.
Celebrity Cruises said the private tour was not affiliated with the cruise line.