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Prince William was last night mourning a "close friend" who was among four soldiers killed by a bomb in the southern Iraq city of Basra.
Joanna Dyer, 24, a 2nd lieutenant, died alongside three other soldiers and a civilian interpreter when their Warrior armoured vehicle was destroyed by a "colossal" blast.
The other troops were named as Corporal Chris O'Neill, 27, Private Eleanor Dlugosz, 19 and Kingsman Adam Smith, also 19.
Passing out in the same company as Prince William in December after a year's officer training, Second Lieutenant Dyer decided to deploy immediately to Iraq to gain operational experience.
Attached to the Second Batallion of the Duke of Lancaster's Regiment, she quickly gained a reputation as a highly competent officer. At Sandhurst she would have also known Prince Harry, who goes to southern Iraq next month with the Blues and Royals.
Prince William said yesterday he was deeply saddened to hear of Dyer's death.
His spokesman said: "Jo was a close friend at Sandhurst and he is very much thinking of her family and friends and they will remain in his thoughts and prayers."
The Oxford graduate had telephoned her family a few weeks ago to reassure them after a large bomb had detonated close by in Basra. A relative said: "She told them, 'You might see it on TV but don't worry, I was not involved. I'm OK'." But, tragically, that's not the case now.
"She's not the first to die in Tony Blair's war and she won't be the last." With a father and mother who had served in the Army and a sister in the Intelligence Corps, joining up would have been a natural step. Her father, Lt Col Neil Dyer, formerly of the Royal Army Ordnance Corps, was a contemporary at Sandhurst of Capt Mark Phillips, the Princess Royal's ex-husband, while her mother, Annie, was a captain in Queen Alexandra's Royal Army Nursing Corps. Her sister Holly is also serving in Iraq but was at home on leave yesterday.
Despite Army regulations banning women from fighting in infantry units, Dyer carved out a role that put her close to the heart of combat operations. A photograph released of the soldier shows her holding an SA80 assault rifle with laser sights, night-vision goggles, the latest body armour and pouches stuffed with ammunition.
Battalion friends described her as a "genuinely selfless person" who "had a thirst for knowledge and wanted to experience all she could".
The officer received a huge amount of mail from friends and always spoke with great pride about her family and boyfriend. "She will be remembered as the girl who could light up a room," her friends said. "Jo was a privilege to have known and we will sorely miss both her and her infectious smile."
Lt Col Mark Kenyon, the commanding officer of the regiment, said: "From a very early stage, it was clear that Jo was a talented and energetic officer determined to make the most of her deployment to Iraq. Her enthusiasm was boundless and her contribution to our operations was invaluable. We very quickly came to think of her as one of us."
Smith's family said: "No amount of words can describe how much we are hurting. We keep thinking, hoping it's not real and we will wake up from this nightmare.
"Adam was the most wonderful and beautiful person anyone could wish to meet, he always had a smile on his face and loved life so much."
Military commanders were said to be reviewing tactics after the Warrior vehicle, regarded as highly robust, was destroyed on Thursday morning. There are several dozen Mastiff armoured trucks in southern Iraq that are more resilient against mines but do not have the firepower of Warriors.
Police in Basra indicated the explosion was caused by a new type of bomb. Major General Mohammed Moussawi said: 'These are new bombs that haven't been used and do not have a precedent here."
The blast left a crater several metres across and a metre deep.
US and British forces have accused neighbouring Shi'ite Iran of supplying Shi'ite militias with "explosively formed penetrators" (EFPs), a particularly deadly type of explosive that can destroy a main battle tank.
These bombs are normally placed on the side of the road and fire a metal projectile embedded in the device into the target at high speed.
But a Western explosives expert in Iraq said it appeared from photographs of the crater that the blast had been caused by a commercial landmine, not by an EFP.
The deaths brought to six the number of British soldiers killed in Iraq last week, one of the deadliest for British forces since the 2003 invasion.
