A British journalist has been killed in an explosion in southern Afghanistan, the UK's Ministry of Defence has said.
Sunday Mirror defence correspondent Rupert Hamer, 39, was embedded with the US Marine Corps when his vehicle was hit by a bomb near Nawa in Helmand.
The father-of-three's Mirror colleague, photographer Philip Coburn, 43, is in a serious but stable condition.
Mr Coburn is due to be flown back to the UK on Monday and will be treated at Selly Oak Hospital in Birmingham.
A US marine was also killed in the blast on Saturday, and five marines were seriously injured.
It had initially been reported that an Afghan soldier had also been killed but that was later corrected.
Mr Coburn, from Larne in County Antrim, broke one leg and had the other amputated below the knee, his brother Nigel told the BBC.
The Mirror journalists had flown to the region on New Year's Eve for a month-long assignment.
Mr Hamer had been a Sunday Mirror journalist for 12 years and was married with children aged six, five and 19 months.
Sunday Mirror editor Tina Weaver said: "Rupert believed that the only place to report a war was from the front line and, as our defence correspondent, he wanted to be embedded with the US Marines at the start of their vital surge into southern Afghanistan."
Colonel Richard Kemp, a former commander of British forces in Afghanistan, knew Rupert Hamer
She added: "Affectionately known as Corporal Hamer in the office, he was a gregarious figure, a wonderful friend who was hugely popular with his colleagues."
UK Prime Minister Gordon Brown said he was "deeply saddened by this tragic news".
He said: "My heartfelt thoughts and sympathies are with the families, friends and colleagues of Rupert and Philip.
"Their courage, skill and dedication to reporting from the front line was incredibly important and ensured that the world could see and read about our heroic troops.
"Their professionalism and commitment to our forces will not be forgotten."
Sun political editor Tom Newton Dunn, who worked as defence editor alongside Mr Hamer, said: "Rupert was not just an excellent journalist in his field but also a thoroughly nice person and I don't think he had an enemy in Fleet Street, let alone in the armed forces."
A former commander of British forces in Afghanistan, Col Richard Kemp, knew Mr Hamer and said he had worked very closely with the military.
He said: "You won't hear a bad word said about him. He was extremely well liked and well respected as a journalist, he was fearless in his reporting, he wouldn't let anybody off the hook easily, but he also understood the way the military worked.
"He had great empathy with soldiers in particular on the ground and some of the work he did for the Sunday Mirror without a shadow of a doubt helped improve the lot of the soldier who was fighting in Afghanistan and elsewhere."
Chris Hughes, the Daily Mirror's security correspondent, said the atmosphere in the newsroom was one of "deep shock".
"Lots of people phoning in - journalists and military types phoning in expressing how sad they are to discover that Rupert, who was a friend to many of them, has been killed," he said.
Defence Secretary Bob Ainsworth said Mr Hamer and Mr Coburn had accompanied him on his most recent trip to Afghanistan.
"I got to know them well and I was impressed by their hard work and professionalism," he said.
"My thoughts and deepest sympathies are with the families, friends and colleagues of both men at this extremely distressing time."
Conservative leader David Cameron sent his condolences to Mr Hamer's family, adding British journalists in Afghanistan did a "crucial job".
Mr Hamer is the second foreign journalist to be killed in Afghanistan in recent days.
Michelle Lang, 34, from Canada's Calgary Herald, died along with four Canadian soldiers in a roadside bomb attack at the end of December.
News of Mr Hamer's death came as the head of the Army told BBC Radio 5 live he expected to see fewer British military casualties in Afghanistan from the end of this year.
And General Sir David Richards said he believed it would be possible to bring down the number of troops in Afghanistan in about 18 months.
"The essence of our military operation is likely to remain broadly as it is today," he said.
"I personally anticipate as we get this business of 'mass' right - the numbers of boots on the ground, a result of allied enhancements and a growth in the Afghan army and police - that I would see a diminishing level of casualties from the end of this year.
"But it could be a tough year until we reach that."
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