"The death of five brave soldiers in a single incident is a terrible loss. My thoughts, condolences and sympathies go to their families, loved ones and colleagues. I know that the whole country too will mourn their loss.
"They fought to make Afghanistan more secure, but above all to make Britain safer from the terrorism and extremism which continues to threaten us from the border areas of Afghanistan and Pakistan. I pay tribute to their courage, skill and determination. They will never be forgotten.
"It is my highest priority to ensure our heroic troops have the best possible support and equipment - and the right strategy, backed by our international partners, and by a new Afghan government ready to play its part in confronting the challenges Afghanistan faces. Our troops deserve nothing less. My commitment to them remains unshakeable."
CONSERVATIVE LEADER, DAVID CAMERON
"I was deeply shocked to hear of the deaths of five British soldiers in a single incident in Helmand Province, and the horrific circumstances in which it appears they died.
"I pay tribute, as will the whole country, to their professionalism and their courage, and send my condolences to their families and their friends."
ISAF COMMANDER, GENERAL STANLEY McCHRYSTAL
"I have spoken to the Minister of Interior, Mr Atmar, who shares my deepest regret for this incident and he gave me his assurance that this incident will be fully and transparently investigated.
"We will not let this event deter our resolve for building a partnership with the Afghan National Security Forces to provide for Afghanistan's future.
"There is a deep sense of loss, as I know many others feel, and our heartfelt condolences go out to the family and friends of our fellow soldiers."
FORMER FOREIGN OFFICE MINISTER, KIM HOWELLS
"There are many people who have argued that there is only one way out of this for Britain, America and the 38 other nations who have combatants inside Afghanistan, and that's to train up the Afghan army and the police force so that they can become responsible for their own security, they can sort out Afghanistan's future.
"This is a real blow because it strikes right at the heart of that policy, of that strategy if you like. And it's not just about training, our troops along with the Americans have borne the great brunt of the fight with the Taliban.
"The international community, under the leadership of the UN, I don't think have pulled their weight at all. As a result we have been forced to fight.
"The prime minister has got to generate a debate about how we move forward in Afghanistan. It's no longer good enough just saying that we are there for as long as it takes, because we could be there forever."
COLONEL RICHARD KEMP
"It will undermine trust, certainly in the short term, until we establish exactly what happened.
"It wouldn't at all surprise me now if there aren't a lot of soldiers, British soldiers in Afghanistan, with their fingers very firmly on the trigger when they're around Afghan police and military.
"It will certainly undermine trust, but that trust needs to be built up again by a combination of reviewing the procedures, trying to ensure that this kind of incident doesn't happen again or reducing the risk of it.
"The risk is back here, a shaking of political and public support for what's going on in Afghanistan. We've got to deal with this problem by out-matching the Taliban on the ground.
"I don't think it's beyond hope. In my view as long as we put the relevant effort and resources in, we can win this."
FORMER UN MISSION DEPUTY HEAD, PETER GALBRAITH
"It is a terrible tragedy but it is, I won't quite say inevitable, but it is not surprising.
"The process of police training and recruiting has been very rushed. Normally the police get an eight-week training course. That is actually very short and there isn't a lot of vetting of police before they are hired.
"Actually, in recent months, they shortened the training programme from eight weeks to five weeks because they wanted to get more police boots on the ground in advance of the elections. So there was a real rush to recruit an additional 10,000, particularly in the south, particularly in Kandahar and Helmand provinces.
"So it is not totally surprising that people were recruited who may have had Taliban sympathies or were infiltrated into the police by the Taliban - although I don't know yet whether in this particular episode, that is exactly what happened."
DEFENCE SECRETARY BOB AINSWORTH
"I was extremely saddened to hear of the deaths of these courageous soldiers. My very deepest condolences go out to their families, friends and colleagues as they come to terms with the loss of these outstanding men.
"It continues to be a difficult year in Afghanistan for our brave people who are operating within the most challenging area of the country.
"We owe it to them to show the resolve that they exhibit every day in building security and stability in Afghanistan and protecting the UK from the threat of terrorism."
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