Afghanistan: 6 UK soldiers presumed dead
London - Six British soldiers are missing and are believed killed in Afghanistan, the Ministry of Defence said on Wednesday, taking the British death toll in the country over 400.
The ministry said an explosion had hit the soldiers' Warrior armoured vehicle on Tuesday while they were on patrol in Helmand, the restive southern province where most British troops are based.
"I have the tragic duty to report that six soldiers are missing, believed killed, during a security patrol," said British spokesperson Lieutenant Colonel Gordon Mackenzie.
The servicemen's families have been informed, the ministry added.
A military source in Afghanistan said the possibility that the vehicle had hit a Soviet-era mine had not been ruled out.
Prime Minister David Cameron described it as a "desperately sad day for our country".
"Every death and every injury reminds us of the human cost paid by our armed forces to keep our country safe," Cameron told parliament.
"Our mission in Afghanistan does remain vital to our national security," he continued. "We're there to prevent that country from being a safe haven to al-Qaeda, from where they might plan attacks on the UK or our allies."
Before the explosion, a total of 398 British forces personnel had died while serving in Afghanistan since the start of operations in October 2001.
If confirmed, the deaths would be the biggest British loss of life in a single incident in Afghanistan since a Nimrod aircraft crashed in 2006 after leaking fuel made contact with a hot air pipe, killing 14 crew members.
Britain has around 9 500 troops in Afghanistan, but Cameron announced in July that this would be reduced by 500 to around 9 000 this year. Britain is due to end combat operations in Afghanistan by late 2014.
Cameron stressed the need for a political settlement with Afghanistan's Taliban insurgents.
Britain must "send a very clear message to the Taliban that, whether it is our troops who are there or whether it is Afghan troops who are there, they will not win on the battlefield - they never win on the battlefield", he said.
"Now it is time for a political settlement to give this country a chance of peaceful progress."
General Sir David Richards, Britain's Chief of Defence Staff, said the six missing soldiers had been doing "a dangerous but important job".
"Increasingly the Afghans themselves are taking the lead in providing security across Helmand. This transition is allowing Afghans to gain the confidence to reject the Taliban and live normal lives," he said.
The number of British troops killed in Afghanistan fell in 2011, but Britain has lost more lives than any country with troops involved in the conflict except the United States.