At least 16 people are missing after a small twin-engine plane crashed amid heavy rain in a river in the Brazilian state of Amazonas.
Four people were rescued and several bodies recovered, but it was unclear how many people were on board.
A short distance from their destination of Manaus the pilots were reported to have contacted air traffic control to say they were turning back.
But the aircraft, which took off from Coari, then disappeared from radar.
According to one report the pilots said they had encountered heavy rain.
The plane is said to have made a forced landing on the River Manacapuru in the Amazon region.
A local fire service official was quoted by Brazil's TV Globo as saying the pilots had been trying to reach a local airport, but the plane fell short by 500 metres.
A rescue effort to find survivors began immediately, and four people were recovered alive, all of whom are said to be in a good condition.
According to local reports several bodies have also been found by divers inside the aircraft, and the authorities fear more will be discovered.
The bad weather in the region is said to be hampering the rescue effort.