Three soldiers from the Royal Regiment Of Scotland killed when an explosion hit their armoured vehicle in Afghanistan have been named.

They were Corporal William Savage and Fusilier Samuel Flint, both from the Royal Highland Fusiliers, 2nd Battalion the Royal Regiment Of Scotland (2 Scots), and Private Robert Hetherington, from 51st Highland, 7th Battalion the Royal Regiment Of Scotland (7 Scots).

Six other men were injured when the Mastiff they were in hit an improvised explosive device (IED) on a routine patrol in Nahr-e Saraj, Helmand Province, yesterday.

It is the first time British troops have died in an armoured Mastiff vehicle since it was introduced to the campaign in 2007.

The Ministry of Defence (MoD) said the men were part of a patrol travelling along Route 611 between Forward Operating Base Ouellette and Patrol Base Lashkar Gah Durai in Nahr-e-Saraj when their vehicle was hit by the IED.

They were airlifted to the military hospital at Camp Bastion where it was confirmed that they had been killed in action. It is not yet known how badly injured the other six soldiers were.

It is understood the explosion was caused by a particularly large bomb and officials are looking into whether insurgents are designing bigger bombs aimed at piercing the Mastiff's heavy armour.

It is unclear whether the bomb penetrated the 23-tonne vehicle or lifted it off the road and turned it over, but it is the first time troops inside a Mastiff have been killed by an IED attack.

Cpl Savage's wife Lyndsey, who is expecting their first child, today paid tribute to the 30-year-old, known as "Sav", who she said "loved being a soldier".

"I am completely devastated by this news but extremely proud of 'Sav' and everything that he has achieved," she said.

"He loved being a soldier!

"I have lost the love of my life and the father of our son. I know his life will live on through so many amazing memories that we shared together.

"He will be deeply missed amongst family, friends and the Regiment."

Cpl Savage joined the 1st Battalion, The Royal Highland Fusiliers (Princess Margaret's own Glasgow and Ayrshire Regiment), in November 2003 after enlisting into the army in April 2003.

He had served in both Iraq and Afghanistan previously and was based in Forward Operating Base Ouellette during his latest tour of Helmand.

A keen sportsman, he enjoyed skiing and was a talented kayak instructor.

Lieutenant Colonel Robin Lindsay, Commanding Officer, The Royal Highland Fusiliers, 2nd Battalion The Royal Regiment of Scotland, said the loss of Cpl Savage would be a "hammer blow" to the battalion and the regimental family.

He said: "We will remember Corporal William Savage as an exceptional soldier, a dedicated leader and a gentleman in the truest sense of the word.

"He was a classic example of a Scottish infantryman; robust, committed and blessed with a fine line in banter.

"Corporal Savage's composed and professional approach had a calming influence on his Platoon and he was seemingly unaffected by the dangers he faced daily in Afghanistan."

He described Cpl Savage as "unflappable", adding: "The loss of Corporal Savage has been a hammer blow to the Battalion and the Regimental family."

Fusilier Flint, 21, from Blackpool, joined the army in November 2011 and was deployed to Afghanistan in March.

He was a motorsports enthusiast and avid Manchester City fan; he was described as the "life and soul of the party" in a statement from his family.

The statement, from the Flint-Broughton family, said: "The whole family is completely devastated.

"Everyone should know that Sam loved his job and made his whole family and everyone that knew him very proud.

"Sam was always the life and soul of the party, a real ladies man, witty funny, the real cheeky chappy.

"He was a loving son, the protective brother, courageous nephew, the caring uncle, the loyal grandson that anyone would wish to have."

Lt Col Lindsay said Fusilier Flint was "brimming with skill and ability".

"Perhaps more importantly, he was quick to form deep friendships with his fellow Jocks and he was always one to help others around him and to give of himself for the benefit of his Section and Platoon.

"He approached everything he did with total motivation and it was clear that his ability matched his ambition. A bright future lay ahead for Fusilier Flint and it is cruel to see that future taken away from him."

Captain Euan Eltringham, who took Fusilier Flint through his basic training at Infantry Training Centre Catterick, described him as a "wonderful phenomenon of a genuine, honest young man".

Warrant Officer Class 2 Stevie Main, Company Sergeant Major, B Company, The Royal Highland Fusiliers, 2nd Battalion The Royal Regiment of Scotland, added: "Fusilier Flint was a Jock that you could always trust.

"He was very keen to learn, hard-working and always offered to help others.

"He had a can-do attitude and he would never let you down.

"Sam Flint epitomised everything that being a Fusilier in the Royal Regiment of Scotland is all about."

Pte Hetherington, 25, was born in the US but raised and educated in Scotland.

He enlisted in the Territorial Army in October 2006 and was mobilised to join The Royal Highland Fusiliers, 2nd Battalion The Royal Regiment of Scotland, for Operation Herrick 18 on November 30.

Lt Col Lindsay described him as epitomising "everything that is excellent about the reserve forces".

"Private Bobby Hetherington was a thoughtful and humorous soldier who was always quick to find the fun in Army life and to keep the chain of command on our toes with his sharp wit and insightful mind," he said.

"He was gregarious and open and this made him a much-liked and respected member of his platoon and the battalion."

Pte Hetherington had plans to attend the Royal Military Academy and become an officer.

Lieutenant Colonel Jon Swift, Commanding Officer First Fusiliers, Transition Support Unit Nahr-e-Saraj, said: "Private Hetherington was on his first tour of Afghanistan and it was immediately apparent to all those who he served alongside in B Company that he was a mature, balanced and thoroughly professional infantryman as well as a model reservist."

Defence Secretary Philip Hammond said: "I was deeply saddened to learn of the deaths of these soldiers, each highly praised and respected by their colleagues and commanders.

"It is clear from the tributes paid to them that they were exceptional men who served their country with distinction.

"My thoughts go out to the families and friends of these brave men at this very difficult time."

Brigadier Rupert Jones MBE, Commander Task Force Helmand, said: "The loss of these three brave Scottish soldiers comes as a great blow to everyone in the Task Force, but leaves us all the more determined in our task to do justice to their memory.

"Their families are in our thoughts and I hope that they can draw a little comfort from the affection in which Corporal Savage, Fusilier Flint and Private Hetherington were held by their brothers in arms and from the courage they displayed."