Investigators have detected a signal from a black box recorder of a Lao Airlines plane that plunged into the Mekong River last week killing all 49 people on board.
The airline said on Monday the bodies of 43 of the victims had been recovered from the swollen river in Laos, many kilometres downstream from the crash site.
The turboprop ATR-72 went down in stormy weather last Wednesday near Pakse airport in Champasak province, sinking to the bottom of the river.
More than half of the passengers and crew were foreigners.
Laos authorities said investigators detected a signal from the recorder - which may hold clues to the cause of the crash - but their efforts to reach it were being hampered by strong currents and poor visibility.
"We are 80 per cent confident about the location of the black box. It is located about 400m away from the crash site," Yakua Lopankao, director general of the country's department of civil aviation, told AFP.
Powerful currents have forced divers to use ropes to guide them through the murky waters, he said, adding that only parts of the submerged plane have been found.
"It's difficult for divers to go down because the water is not clear. It's fast-flowing and about 12 to 13m deep," he added.
The airline said two more bodies had been retrieved on Monday about 25km from the crash site.
According to an official passenger list, there were 16 Laotians on board, seven French travellers, six Australians, five Thais, three South Koreans, two Vietnamese, and one national each from the United States, Canada, Malaysia, China and Taiwan.
There were also five crew, including the Cambodian captain.
Impoverished Laos, a one-party communist state, observed a nationwide minute's silence on Monday afternoon to remember the victims of the crash, which is the nation's worst known air disaster.