Colleagues and army chiefs yesterday paid tribute to the bravery of two soldiers who were killed in an explosion in Afghanistan.

Sergeant Stuart Millar, 40, and Private Kevin Elliott, 24, of The Black Watch, 3rd Battalion The Royal Regiment of Scotland, were on foot patrol north of Lashkar Gah District, southern Helmand, on Monday when they were injured in the blast, which is believed to have been caused by a rocket-propelled grenade.

Sgt Millar, who married last year and had a young daughter, was the oldest soldier in the company and was remembered for mentoring younger colleagues as well as for his "friendship, honesty, integrity and humour".

Pte Elliott had been with the Army since 2002 and had planned to return to civilian life earlier this year but decided to sign back on at the last minute because he would have missed his colleagues and wanted to remain "in the thick of the action".

The two deaths bring the number of British military personnel killed in Afghanistan since operations began in 2001 to 210.

Sgt Millar, who was known as Gus, joined the Army in 2000 after serving in the Territorial Army and was deployed to Afghanistan in April as a mortar fire controller.

His colleagues paid tribute to his sense of humour, displayed when he told an ITN news crew that a long fire fight with insurgents on the first day of Operation Panther's Claw earlier this year had delayed his "morning brew".

Lieutenant Colonel Stephen Cartwright, Commanding Officer of The Black Watch, 3rd Battalion The Royal Regiment of Scotland, said: "It was typical of the man: in the thick of the action, professional expertise to the fore, combined with his wonderfully positive and humorous style.

"It was no surprise to hear that in this tragic incident, he was the first man on the roof in the defensive position, the first to volunteer to protect his colleagues in a dangerous area. "

In a statement, Sgt Millar's family said: "Gus always wanted to be a soldier from a very young age. He passionately enjoyed his job and often talked fondly about his colleagues and friends.

"He was very brave and is a credit to both our family and the Army. We are really proud of him as a father, son, brother and soldier."

Pte Elliott, from Dundee, had served in Iraq and Northern Ireland before being deployed to Afghanistan.

Captain Harry Gladstone, Fire Support Group Commander said: "Pte Kev Elliott was a unique soldier. He was excellent in the field and had a brilliant sense of humour. He was naturally fit and most importantly he was very loyal to his friends. Pte Elliott died in tragic circumstances doing what he loved.

"I remember talking him shortly before we left Inverness to deploy to Afghanistan in March. He was dressed in his civilian clothes, having been de-kitted, and about to walk out of Fort George back to civilian life when he decided to sign back on. When asked why he decided to sign back on he simply said "I didn't want to miss the boys." This comment sums up his attitude to the Army."

Pte Elliott is survived by his mother and grandmother, two brothers and two sisters. In a statement, his family said: "Kevin was a loving son, brother, grandson, brother, nephew, uncle and cousin who will be sorely missed by the whole family."