British Forces in Afghanistan have been dealt a huge personal blow with the loss of the most senior infantry commander to be killed in action since the Falklands war.

Lieutenant-Colonel Rupert Thorneloe, 39, the commanding officer of the 1st Battalion Welsh Guards, was killed when the Viking armoured tracked vehicle that he was travelling in was blown up in Helmand.

Trooper Joshua Hammond, 19, of the 2nd Royal Tank Regiment, was also killed and six soldiers were wounded, some critically. The Viking, which has proved vulnerable to Taleban roadside bombs, was blown up about five miles north of Lashkar Gah, the provincial capital.

The colonel, who commanded the 1st Welsh Guards for less than a year, had been visiting troops engaged in an operation codenamed Panchai Palang (Panther’s Claw). He was described as a born leader destined for the top.

His wife, Sally, mother of their two young daughters, Hannah and Sophie, said: “I could not have asked for a more caring, adoring and loving husband and father. While he was with us our lives were filled with joy and happiness. Hannah always said the best bit of Daddy was his coming home and that will never happen again.”

The deaths, which brought the number of British fatalities to 171 since 2001, came as 4,000 US Marines and 650 Afghan soldiers and police officers launched the biggest-ever operation against the Taleban in Helmand.

Colonel Thorneloe had wanted to check on his men, who are engaged in holding ground in Babaji and Nad-e-Ali, north of Lashkar Gah, to protect locals before the Afghan presidential elections on August 20.

Defence sources said that it was vital for commanding officers to be seen with their troops, taking the same risks. The Welsh Guards had already lost two officers in two months. Major Sean Birchall, 33, a company commander, was killed on June 19 by a roadside bomb, and Lieutenant Mark Evison, 26, was shot fatally on May 9.

The last battalion commanding officer to be killed in battle was Lieutenant-Colonel “H” Jones, of the 2nd Battalion The Parachute Regiment, who died under a hail of machinegun fire while leading his men against Argentine positions in Goose Green. He was awarded a posthumous Victoria Cross.

Chris Keeble, who, as a major in 1982, was second-in-command of 2 Para and had to take immediate control of the battalion, told The Times: “We lead from the front. The death of a commanding officer is no less and no more of a tragedy than the death of a private soldier.”

General Sir Richard Dannatt, Chief of the General Staff, said that Colonel Thorneloe was “an outstanding commanding officer and a born leader”.

A spokesman for the Prince of Wales, who is Colonel of the Welsh Guards and is understood to have known Colonel Thorneloe well, said that he was “deeply saddened”.

At least seven soldiers and Royal Marines have been killed in the Viking, which was sent to Afghanistan in October 2006 to ferry troops between forward operating bases. Its armour has proved vulnerable to large explosions. The MoD is planning to replace it, but not until next year.

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