Four US marines have died after their Osprey aircraft crashed in a Norwegian town in the Arctic Circle during a NATO exercise unrelated to the Ukraine war, authorities say.
Norwegian Prime Minister Jonas Gahr Stoere tweeted that the group died in the crash on Friday night.
The cause of the crash is under investigation, but Norwegian police reported bad weather in the area.
The marines were taking part in a NATO exercise called Cold Response.
The US said the identities of the marines would not be immediately released, in keeping with US Defence Department policy of notifying relatives.
The aircraft was an MV-22B Osprey.
It had a crew of four and was out on a training mission in Nordland County in northern Norway, the country's armed forces said in a statement.
It was on its way north to Bodoe, where it was scheduled to land just before 6pm (local time) Friday.
The Osprey crashed in Graetaedalen in Beiarn, south of Bodoe.
Police said a search and rescue mission was launched immediately.
At 1:30am (local time) on Saturday, the police arrived at the scene and confirmed that the crew of four had died.
The annual NATO drills in Norway are unrelated to the war in Ukraine.
This year they include around 30,000 troops, 220 aircraft and 50 vessels from 27 countries. Non-NATO members Finland and Sweden are also participating.
The exercises began on March 14 and end on April 1.
Military exercise to carry on
No cause was given for the crash, but the Norwegian armed forces said that Cold Response "will carry on as planned, with the measures we have to take due to the weather".
A Norwegian rescue helicopter spotted the crash site late Friday and local Red Cross crews were assigned to assist police on the ground, according to local media reports.
A Norwegian newspaper said Red Cross members drove close to the crash site with scooters and marked the trail with GPS for police in what they described as extremely difficult weather conditions early on Saturday.
"It was a special night, it was a real storm. There were five of us driving towards the scene of the accident. There was one metre of visibility, snow and storm in the mountains," Red Cross team leader Oerjan Kristensen told the newspaper.
"I guess it was a wind gust of 30-40 metres per second.
Bad weather hampers rescue efforts
Mr Kristensen added that the rescue operation is being hampered by the risk of landslides in the mountains, and the remoteness of the crash site.
Police launched an investigation into the crash and accident commission members and police representatives were due to arrive at the crash site on Saturday.
Lieutenant General Yngve Odlo, head of the Norwegian Armed Forces' operational headquarters, said that Cold Response would continue despite the crash.
"Right now there is full focus on ending the rescue operation, taking care of the people and then there will be a normal procedure with causation," Mr Odlo was said.
The first Cold Response exercise was held in 2006, and the drills have been conducted a total of eight times over the years. They take place in south-eastern, central and northern Norway.
AP/ABC
