Some 4,000 British personnel have been involved in Operation Moshtarak
A British soldier has been killed in an explosion in Afghanistan while taking part in Operation Moshtarak.
The soldier was part of 28 Engineer Regiment, attached to the Brigade Reconnaissance Force.
The soldier died following an explosion near a checkpoint in the Nad Ali district of Helmand province.
His next of kin have been informed. His death takes the number of British service personnel killed in the conflict to 266.
The soldier was on a foot patrol against insurgents in an area about three kilometres south of checkpoint Shamal Storrei, to the west of Lashkar Gah, when he was caught by an explosion on Friday morning.
The spokesman for Task Force Helmand, Lt Col David Wakefield, said: "It is my sad duty to inform you that a soldier from 28 Engineer Regiment, serving with the Brigade Reconnaissance Force, was killed this morning.
"We have lost one of our comrades but his courage in the face of danger, relentlessly taking the fight to the enemy, will be remembered."
Operation Moshtarak, involves up to 15,000 Nato troops clearing the Taliban from parts of southern Helmand.
Some 4,000 British personnel have been involved in the offensive, alongside US and Afghan forces, with the aim of securing government control in the towns of Marjah and Nad Ali.
On Thursday two servicemen, an airman and a soldier, were killed in Afghanistan. Neither of them was involved in Operation Moshtarak.