Fourteen British service personnel have died after their aircraft crashed in Afghanistan, the MoD has said.
Twelve RAF personnel, a Royal Marine and an Army soldier were among those who died in the crash in the southern province of Kandahar.
The aircraft belonged to NATO-led international force against the Taleban.
An International Security Assistance Force spokesman said "enemy action had been discounted at this stage".
Earlier, NATO said its forces had launched a major offensive against known hideouts of Taleban insurgents in the Panjwayi district of Kandahar, with the aim of driving them out of the area.
There was no indication of an enemy attack on the plane, which was not a fighter jet, Maj Scott Lundy said.
MoD Helpline
A special helpline is available on 08457 800 900 for families concerned about relatives
The crash came as Afghan and Nato troops began a major anti-Taleban drive in the Panjwayi district of Kandahar which has seen months of fighting.
Afghanistan is experiencing its bloodiest period since the fall of the Taleban in 2001. Much of the fighting has been concentrated in the south.
The plane came down about 20 km (12 miles) west of the city of Kandahar, Maj Lundy of the International Security Assistance Force (Isaf) said.
It was "supporting a Nato mission. It went off the radar and crashed in an open area in Kandahar."
Nato forces are at the scene but there is no word on how many people were on board. A large Canadian contingent is based in Kandahar province.
A local tribal elder told the Associated Press news agency by phone that the wreckage of the plane was burning in an open field.
"I can see three or four helicopters in the sky, and coalition forces are also arriving in the area," he said.
On Thursday, a Dutch F-16 fighter pilot was killed after his plane crashed in the southern province of Ghazni.
Officials said the crash was believed to be an accident.
It`s being reported as an accident down here and Taliban stinger claims are being discounted.
Sad day indeed, here`s to`em.
Rest easy, aye,
They shall grow not old, as we that are left grow old.
Age shall not weary nor the years condemn.
At the going down of the sun, and in the morning, We Will Remember Them
Flt Lt Steven Johnson, Flt Lt Leigh Anthony Mitchelmore, Flt Lt Gareth Rodney Nicholas, Flt Lt Allan James Squires, Flt Lt Steven Swarbrick, Flight Sgt Gary Wayne Andrews, Flight Sgt Stephen Beattie, Flight Sgt Gerard Martin Bell, Flight Sgt Adrian Davis, Sgt Benjamin James Knight, Sgt John Joseph Langton and Sgt Gary Paul Quilliam.
The soldier who died was Lance Corporal Oliver Simon Dicketts from the Parachute Regiment.
The Royal Marine was named as Joseph David Windall.
I wish to extend my heartfelt condolences to the families of those military personnel who were killed in Afghanistan. These courageous people were trying to make Afghanistan a safer and more stable country for the Afghan people. The demise of the Taliban regime meant that Afghans particularly women were given back their human rights.
Many of us are grateful to those who sacrificed their lives and those still selflessly serving and risking their lives out there.
I wish to express my condolences to the 12 RAF aircrew and 2 army personnel and indeed the small community in Kinloss and to all the families and serving airmen. It is a sombre day for all those connected with the squadron, it will certainly be a sombre day going into work today.
