Cameron commits to Afghan war as four die

The servicemen, including one from the 1st Battalion The Yorkshire Regiment, died when the Ridgeback armoured vehicle they were in came off the road and ended up in a deep canal in Helmand on Wednesday.

The other three soldiers were all from the 1st Battalion The Mercian Regiment and the incident is thought to be a tragic accident rather than having been caused by enemy action.

Their deaths take the total British death toll to 307 – including 18 this month alone.

Lieutenant Colonel James Carr-Smith, the army's spokesman in Helmand, said the team were en route to help at an incident at a nearby checkpoint when the vehicle left the road. "They will be sorely missed and their actions will not be forgotten," he said.

Reacting to the news as he travelled to the G8 summit in Canada, the Prime Minister paid tribute to their service and warned of further "difficult times" ahead in Afghanistan.

Mr Cameron said: "This is a completely tragic case. Obviously we are paying a very high price for what we are doing in Afghanistan, but I remain absolutely committed to making sure that we build up the Afghans' own capability and security so that they can take responsibility for their country and we can come home.

"There is no doubt that we have had a difficult few months in terms of casualties and it will be a difficult summer, I have no doubt about that. But we have to ask ourselves the question all the time – are we doing the right thing by conducting his counter-insurgency operation?"

Meanwhile the family of the fourth Royal Marine killed in four days in Afghanistan said last night that they would never forget his sacrifice. Sergeant Steven Darbyshire, 35, from 40 Commando, was killed in a firefight in Sangin in Helmand Province on Wednesday while on a joint patrol with Afghan soldiers to reassure local people.

Paying tribute, his family, from Wigan, said: "He was proud to wear the uniform and served his country as the consummate professional. He died doing the job he so loved."

Relatives and friends of

three soldiers killed in Afghanistan wept as their bodies were repatriated back to the UK yesterday.

Trooper Ashley Smith, 21, from York, of The Royal Dragoon Guards, Corporal Taniela Rogoiruwai and Kingsman Ponipate Tagitaginimoce, both of 1st Battalion The Duke of Lancaster's Regiment, were driven through Wootton Bassett, Wiltshire where hundreds lined the high street in silence.

The British general who has taken temporary command of all 140,000 Nato troops in Afghanistan spoke of his determination not to be affected by the sacking of his boss US General Stanley McChrystal.

Lieutenant General Sir Nick Parker said: "While we face a tough summer ahead, strong leadership, the focus of the soldiers on the ground and our partnership with Afghan security forces, will ensure that we defeat an insurgency that has brought so much suffering to Afghanistan."