An investigation is under way to determine why a Lynx helicopter crashed in southern Afghanistan, killing five British service personnel.
Investigators from Britain’s Military Aviation Authority have cordoned off the crash site near Kandahar and will inspect the wreckage of the light utility aircraft.
The Ministry of Defence has denied claims by the Taliban that insurgents shot down the helicopter, saying initial investigations indicated a technical problem during the routine flight rather than enemy action.
The inquiry is likely to look at the aircraft’s log books and other documentation, in addition to weather conditions and whether the helicopter was carrying out an authorised job according to its capabilities, experts said.
It is not thought that other Lynx helicopters in use in Afghanistan will be immediately grounded following the crash.
A spokeswoman said: “The investigation is now under way, and the area of the crash has been cordoned off.
“We cannot go into further details. At this stage it is not known how long the investigation might last or when investigators will deliver their report, but it will be a thorough inquiry.”
Three of the servicemen who died were from the air corps, based at RAF Odiham in Hampshire. A Royal Air Force serviceman stationed at the same base also died, along with a member of the army reserve.
The next of kin of all five servicemen have been informed of their deaths but none has yet been named.
It is the third biggest single loss of life of British troops since the conflict in Afghanistan began in 2001, and brings the total number of UK service personnel killed there to 453.
British Prime Minister David Cameron last night paid tribute to those who died, saying: "My heart goes out to the families and friends of those killed in this terrible tragedy."
The aircraft, believed to be a Westland Lynx Mk 9 helicopter, went down yesterday morning in the Takhta Pul district of Kandahar, some 50km from the Pakistan border.
Lynx helicopters are used for a wide range of roles, including transport, surveillance, resupply and operational support. They are seen as “work horses” and carry a crew of three, including a pilot, co-pilot and gunner. It is believed that the other two military personnel on board may have been travelling as passengers.
The crash is the worst incident involving a British military helicopter in Afghanistan since the war began there more than 12 years ago.
Previously, three Chinook crashes and one Apache emergency landing left no fatal victims, according to reports.
In September 2006 a Nimrod surveillance aircraft from RAF Kinloss in Scotland exploded in mid-air near Kandahar, killing all 14 servicemen on board, while in March 2012 six soldiers died when their Warrior armoured fighting vehicle was hit by an improvised explosive device in Helmand Province.
Yesterday’s incident equals the previous worst disaster involving a British helicopter, when a Lynx aircraft crashed in Basra City, Iraq, in May 2006 killing the five service personnel on board.
The deadliest single incident for US troops came in August 2011, when the Taliban shot down an American Chinook helicopter near Kabul, killing 30 Americans and eight Afghans.
Nato forces are currently preparing to withdraw combat troops by the end of this year, with responsibility for fighting the Taliban uprising handed over to the Afghan army and police.
So far this year, 23 Nato troops are thought to have been killed in Afghanistan.