A British military helicopter has crashed in the Czech Republic killing six British soldiers.
Four soldiers and two crew died when the Lynx helicopter came down near Brno.
A Czech defence spokesman said the soldiers were taking part in an Anglo-Czech military training exercise called Operation Flying Rhino.
The Ministry of Defence said it was now investigating the crash, which occurred at about noon BST on Thursday and involved troops based in Germany.
An MoD spokesman told the BBC its investigators would be working with Czech emergency services at the scene, where six bodies were recovered.
Those killed were two air crew and four soldiers flying as passengers. There were no survivors.
"Their families have now been informed," an MoD spokesman said.
The MoD is also deciding whether to cancel the remainder of the 10-day exercise, due to run until 17 September, BBC defence correspondent Jane Hughes said.
An MoD spokesman confirmed the exercise involved British soldiers based in Germany.
Part of the helicopter's wreckage was found submerged in a creek
An earlier MoD statement said a UK team had attended with Czech emergency services after the crash at 1204 BST.
British Army troops based in Germany have in recent years increasingly taken to taking part in exercises in Poland and the Czech Republic.
Some reports suggest the helicopter had been flying low to the ground when it came down near Namest nad Oslavou, about 110 miles (180 km) south east of Prague.
Czech defence spokesman Andrej Cirtek said the helicopter had been taking part in a joint Czech-British exercise codenamed Flying Rhino.
Crew: Two, plus up to 10 troops and one door gunner
Engines: Two 850 shp Rolls-Royce Gem 41s
Max Speed : 330 kph
Armament (if fitted): Eight TOW Anti-armour Missiles, two to four 7.62mm GPMG machine guns
Source: Ministry of Defence
He said it was not immediately clear what had caused the crash.
Lynx helicopters have a history of engine and rotor problems but it is not clear if mechanical failure was to blame on this occasion.
Sabina Introvicova, of the Czech air force, told the BBC it was a "really terrible situation" for everyone involved. She confirmed there had been no civilian casualties.
The head of the regional emergency services, Jan Sedlak, said rescue workers had found six bodies but no survivors at the scene in an uninhabited valley.
Part of the helicopter was burnt, he said, with the remaining wreckage submerged in a creek.
Czech radio reports have quoted eye-witnesses as saying the helicopter was caught in high-voltage electric wires near the river.
A local reporter at the scene said rescuers had been searching for possible survivors who might have jumped from the aircraft.
Czech news agency CTK quoted rescue workers at the scene saying the soldiers died in a fire that broke out after the aircraft came down.
According to the website of the British Embassy in Prague, Flying Rhino forms part of an extensive programme of bilateral military activity between the UK and its Nato ally.
Those killed in the crash were part of a 450-strong British contingent which arrived at the Namest nad Oslavou airbase on Monday for the 10-day exercise.
The exercise is designed to improve the way the two countries work together and help integrate the Czech Republic into Nato.
British and Czech pilots were searching for ground targets and then simulating attacks from the air as part of their training.