Two British Royal Marines were killed in an explosion in southern Afghanistan, the Ministry of Defence confirmed today.
The pair, from UK Landing Force Command Support Group, were taking part in a joint patrol with soldiers from Afghan security forces when their vehicle was struck by an explosive device in the Garmsir district of Southern Helmand yesterday afternoon.
Commander Paula Rowe, of Task Force Helmand, said: "This is a tragic blow to us all in the task force, but our loss is nothing compared to that of their families and loved ones.
"Our thoughts and prayers are with them at this terrible time."
Next of kin have been informed.
The pair were operating as part of Task Force Helmand's Information Exploitation Group, which is responsible for gathering information to improve situational awareness and to gain an advantage over enemy forces.
The incident happened at 4.47pm local time yesterday.
The marines were on a routine patrol and the cause of the explosion is not yet known.
Brigadier General Richard Blanchette of the Nato-led International Security Assistance Force (ISAF) said: "Our deepest sympathies go out to their family, friends and fellow soldiers.
"Their lives are irreplaceable to all of us who fight for the peace and stability of Afghanistan."
The soldiers' next of kin asked for a 24-hour period of grace before more information is released, the MoD said.
The deaths bring the number of British services personnel killed in Afghanistan since operations began to 124.
On November 4 the first Nepalese Gurkha soldier was killed fighting in the country.
Yubraj Rai, 28, who served with the 2nd Battalion The Royal Gurkha Rifles, was killed while on patrol near Musa Qaleh in southern Afghanistan.
In a separate incident today, a suicide car bomber in eastern Afghanistan killed 20 civilians and an American soldier, a US military spokesman said.
Lieutenant Commander Walter Matthews said the bomber attacked a US convoy in a crowded market in the Bati Kot district of Nangarhar province.
The deaths follow a survey published by ICM Research yesterday, which showed more than two-thirds of the population believe UK troops should be withdrawn from Afghanistan in the next year.
The poll was commissioned by BBC4 ahead of the debate In Afghanistan: Should We Bring Home The Troops?, which will be broadcast at 8pm tonight.
But an MoD spokesman said its most recently commissioned Mori poll showed more than 50% of the public supported the UK armed forces' presence in Afghanistan.
And in a recent Chatham House survey, only 37% of responses called for the withdrawal of British forces.
But the spokesman said using such polls "is not necessarily helpful - there is an important job to be done in Afghanistan and we must win public support for it".
"The UK is committed to maintaining troops in Afghanistan until the government of Afghanistan (GoA) has built sufficient capacity to maintain a stable security situation and the rule of law," he said.
"UK military and civilians are playing a vital role in helping the Afghan government to build a better future for Afghanistan. In turn, a stable and secure Afghanistan is in the UK national interest, and we must not let it become a training ground for terrorists."
He added: "We need to do more to explain to the UK public why it's so important that the UK continues to support the GoA and the international presence in Afghanistan."