Rifleman James Brown and L/Cpl David Kirkness died on Tuesday
Two UK soldiers killed in Afghanistan sacrificed their lives to stop suicide bombers attacking a packed marketplace, their commanding officer has said.
L/Cpl David Kirkness, 24, of West Yorkshire, and Rifleman James Brown, 18, from Kent, both of 3rd Battalion The Rifles, died on Tuesday.
They were killed by an explosion at a vehicle checkpoint near Sangin in Helmand. Two Afghan soldiers also died.
Lt Col Nick Kitson said they had "averted a much larger tragedy".
The joint patrol consisted of four Afghan soldiers, 15 British soldiers from 3 Rifles and an interpreter. They had set up a vehicle checkpoint near the main bazaar area.
Rifleman James Brown's mother Tracy pays tribute to her "beautiful boy"
The MoD said reports from the scene suggested a motorbike carrying two men came towards the checkpoint and drove straight into it. Eyewitnesses have also reported a double explosion.
Officials say the insurgents may not have been expecting the checkpoint and had probably planned on attacking the civilians in the market.
Within minutes, an RAF Chinook helicopter landed close to the incident to evacuate the British casualties, despite coming under attack from small arms and grenades.
L/Cpl Kirkness and Rifleman Brown were pronounced dead shortly after. The incident is now under investigation.
'Comfort and pride'
L/Cpl Kirkness, from Morley in Leeds, was described by his commanding officer as "a first-class leader".
He said: "To the younger riflemen he gave inspiration and guidance, earning their respect and instilling in them the confidence and understanding to guide them through their current challenges.
"He balanced courage and grit with compassion and consideration, winning trust, admiration and friendship wherever he went.
"Tragic as his loss is, we take comfort and pride from the fact that he and the soldiers who died with him, both Afghan and British, averted a much larger tragedy.
"Their sacrifice prevented two suicide bombers from reaching their intended target, the bustling and ever more prosperous Sangin bazaar, packed with local Afghans going about their daily business."
A statement from his parents, Christopher and Margaret Kirkness and his three-year-old daughter, Brooke, said: "We would like to thank family and friends for their support over these difficult times.
"If you knew David, you had to love him - it was impossible not to. And in David's own words, 'If you didn't know me, hard luck.' He will always be in our hearts."
The family of Rifleman Brown, from Orpington, said: "James Stephen Brown, a son, brother, uncle, boyfriend and a friend. You were a true hero and will be dearly missed.
"We all love you so much. You died a hero living your dream and you will always be in our thoughts. Your actions will always speak louder than words ever could."
Lt Col Kitson said he was a young man "showing the promising signs of a soldier with a bright future".
He said: "He had already made a lasting impression on his fellow riflemen with his immense courage, infectious confidence and talent for making people laugh.
"What he lacked in experience he made up for in enthusiasm, young yet keen to please and with a voracious appetite for work and fun in equal measure.
"It is all the more difficult to come to terms with the loss of one so young and we are all deprived of the joy of watching his promise unfold."
Defence Secretary Bob Ainsworth said he was "extremely saddened" to learn of the deaths.
A total of 239 UK service personnel have died in Afghanistan since 2001, including 102 this year.