A soldier from 3rd Battalion The Rifles has been killed while on patrol in Afghanistan, the Ministry of Defence said.
The serviceman was on patrol in the Nad-e-Ali district of Helmand province when he was killed by "enemy action".
Task Force Helmand spokesman Major Ian Lawrence said: "It is with great sadness I must inform you that a soldier from 3rd Battalion The Rifles has died as a result of injuries sustained whilst on patrol in the Nad-e Ali district of Helmand province.
"The thoughts and prayers of all in the task force are with his family and friends at this tragic time."
The soldier's family have been informed and have asked for a 24-hour period of grace before further details are released.
Earlier, the International Security Assistance Force said three US soldiers were killed in an incident in south-west Afghanistan by "an individual wearing Afghan uniform".