The soldier was serving with the Brigade Reconnaissance Force
A soldier from the Household Cavalry Regiment has died in a grenade attack in Afghanistan, the MoD has said.
He was on foot patrol near Sangin in Helmand when the grenade was thrown from behind a wall on Friday afternoon.
A UK military spokesman said he would be "sorely missed". His death was not connected with Operation Moshtarak, a major offensive against the Taliban.
His family have been told. A total of 277 British service personnel have been killed in Afghanistan since 2001.
The MoD said the attack took place 3km (1.9 miles) south of the centre of Sangin.
'Bold and relentless'
Col Wakefield, of the UK's Task Force Helmand operation in Afghanistan, said the soldier was serving with the Brigade Reconnaissance Force (BRF).
"He was part of a BRF operation doing what the soldiers of the BRF have done throughout their tour in Helmand, boldly and relentlessly taking the fight to the insurgents," Col Wakefield said.
"He will be sorely missed by us all and we will remember him."
The soldier is the first member of the Household Cavalry Regiment to be killed in Afghanistan this tour. The regiment is coming to the end of its six-month deployment.
Prince Harry served with the Household Cavalry in Afghanistan for 10 weeks at the beginning of 2008.