The most senior British serviceman to be killed in action in Afghanistan has been described as "a superb commanding officer" who was "destined for greatness".

Lieutenant Colonel Rupert Thorneloe, commanding officer of the 1st Battalion Welsh Guards, was killed along with 18-year-old Trooper Joshua Hammond, of 2nd Royal Tank Regiment, about 8km north of Lashkar Gah in Helmand province on Wednesday.

General Sir Richard Dannatt, Chief of the General Staff, said Lt Col Thorneloe, of Kirtlington, near Oxford, was at the "leading edge of his generation" while his wife Sally said the 39-year-old father-of-two would be "sorely missed".

He had left the Battle Group Headquarters and was on a resupply convoy in order to visit his men who were conducting a major operation in hostile territory, the Ministry of Defence said.

An improvised explosive device was detonated under his Viking Armoured vehicle at about 3.20pm local time, killing him and Trooper Hammond, and taking the number of UK servicemen and women who have died in Afghanistan since operations began in October 2001 to 171.

Gen Sir Richard said his death was "a devastating blow to the Welsh Guards Battle Group and to the Army as a whole".

His wife Sally said he was her "very best friend" and added: "Our daughters Hannah and Sophie will have to grow up without their beloved daddy, although I will see a part of him in them every day. I could not have asked for a more caring, adoring and loving husband and father."

She said their lives would never be the same again. Describing her husband as "a born soldier" and "an inspiration", she said: "I know he led from the front and would not have had it any other way. He cared deeply about his men as he did about so many.

"His charisma, compassion and enthusiasm for all in life will be so sorely missed by his family and many friends but most of all by me who loved him so much."

A Clarence House spokesman said the Prince of Wales, who is Colonel of the Welsh Guards, was "deeply saddened" by his death and would be writing privately both to his family and to his regiment. It is understood Charles knew Lt Col Thorneloe well.