A plane heading for the Everest region has crashed on the outskirts of Nepal's capital, killing all 19 people on board including seven British tourists.
The plane, operated by Sita Air, came down minutes after take-off from Kathmandu. Officials said it crashed into a river bank and caught fire.
Sixteen passengers and three crew were on board the twin-propeller Dornier.
The UK Foreign Office has confirmed the British deaths and said relatives have been informed.
As well as the seven Britons, five Chinese nationals and seven Nepali nationals were on the plane, including the three Nepalese crew, police and aviation officials said.
The British Embassy in Kathmandu said the UK ambassador had gone to Tribhuvan University Teaching Hospital, where the bodies of those who died had been taken.
The cause of the crash is not yet known. However, the general manager of Tribhuvan International Airport, Ratish Chandra Lal Suman, said it appeared that the plane had struck a bird.
He said air traffic control contacted the pilot after noticing an unusual manoeuvre minutes after take-off and the pilot said his plane had hit a vulture.
Mr Suman said the plane had been attempting to get back to the airport when it crashed.
Nepalese officials later said that the flight recorders had been recovered from the wreckage.
They said initial reports suggested the crash happened as the pilots tried to change direction and land again after suffering "technical glitches".
Nepalese Prime Minister Baburam Bhattarai promised to take action to prevent similar accidents, but did not give details.
"I am saddened by the death of the locals and foreign nationals in the plane crash. I pay condolences to the families of the dead," he said.
The Dornier 228 aircraft had been heading for Lukla, the hub for trekking in the Everest region.
The trekking season has just begun in Nepal and thousands of climbers, including many Westerners, head to the country's famous Himalayan peaks.
A spokeswoman for local travel firm Sherpa Adventures said the British group had arrived in Nepal on Wednesday and was due to start trekking on Friday until 16 October.
Police spokesman Binod Singh told the AFP news agency that "the pilots seem to have tried to land it safely on the banks of the river but unfortunately the plane caught fire".
One of the first rescuers to reach the crash site, police officer Bhagwan Bhandari, described the scene as "terrifying".
"There was fire coming from the aircraft. Red flames were reaching up to 20m (65ft) above the ground," he said.
"It wasn't possible to get inside to conduct rescue operations. We could hear blasts from the parts and engines of the aircraft."
Images showed burning wreckage at the crash site and dozens of rescue and security personnel.
British mountaineer Alan Hinkes told the BBC he had taken the flight from Kathmandu to Lukla many times and that problems usually occurred at the Lukla end.
"The landing strip in Lukla is a bit like an aircraft carrier with a mountain at the end of it, with a 1,000ft drop at the end of the runway. Normally crashes happen at that end," he said.
He added: "It is not the safest place to fly, I must admit, but it is what you have to do to get into the mountains."
Aviation accidents involving small aircraft are not uncommon in mountainous Nepal.
In May, 15 people were killed when a plane crashed trying to land at an airport in the north of the country.
And in September 2011, 19 people were killed when a Buddha Air plane crashed during a flight to view Mount Everest.