A plane from Laos' state-run airline crashed in bad weather in the Southeast Asian nation, apparently killing 49 people from 11 countries, the government said.
The Lao government said it was dispatching rescuers to the scene of Wednesday's crash, but the Australian government said it was told no survivors were expected.
The Ministry of Public Works and Transport, which operates Lao Airlines, said 44 passengers and five crew members were on Flight QV301 from the capital, Vientiane, to Pakse in the country's south. Earlier reports had 39 passengers.
"Upon preparing to land at Pakse Airport the aircraft ran into extreme bad weather conditions and was reportedly crashed into the Mekong River," the ministry said in a statement.
The airline flies an ATR 72-600 twin-engine turboprop plane on the 290-mile route. French maker ATR said the plane that crashed had been delivered in March. The aircraft is configured with 68-74 seats, it said.
Thai Foreign Ministry spokesman Sek Wannamethee said his country's embassy in Vientiane was informed that the plane crashed 4-5 miles from the airport at Pakse.
A passenger manifest faxed by the airline listed 44 people: 17 Lao, seven French, five Australians, five Thais, three Koreans, two Vietnamese and one person each from Canada, China, Malaysia, Taiwan and the United States. Korean, French and Thai officials confirmed the totals for their nationalities.
The Lao government said the airline "is taking all necessary steps to coordinate and dispatch all rescue units to the accident site in the hope of finding survivors."
However, a statement from Australia's Department of Foreign Affairs and Trade said "Lao authorities have told our embassy in Vientiane they do not expect any survivors."
The Lao transport ministry statement said the crash is being investigated and the airline hoped to announce its findings on Thursday. A Lao Airlines employee contacted by phone at Vientiane's Wattay airport said a news conference would be held Thursday.
ATR issued a statement from its headquarters in Toulouse, France, declaring that it will fully assist the investigation. It said the Lao Airlines plane had been delivered from the production line in March this year.