A Royal Marine was killed in Afghanistan when the vehicle he was travelling in was caught in an explosion, the Ministry of Defence has said.
The serviceman was fatally wounded south of the capital, Kabul, a spokeswoman said.
His next of kin have been informed.
The serviceman is understood to have been serving with Special Forces but the MoD does not comment on Special Forces deaths.
The spokeswoman said: "It is with great sadness that the Ministry of Defence must confirm that a Royal Marine was killed today, Thursday 22nd December, south of Kabul in Afghanistan.
"He was fatally wounded after the vehicle in which he was travelling was caught in an explosion."
A total of 392 British troops have died since the start of operations in Afghanistan in 2001.
Earlier this week Prime Minister David Cameron indicated he was planning further withdrawals of troops from the country in 2013 after the 500 due to be pulled out next year.
But he again refused to give an exact timescale for how Britain's deployment would be withdrawn ahead of his deadline for all combat troops to be out by the end of 2014.