The soldiers, serving with 40 Commando Royal Marines, were on patrol near Kajaki, in Helmand Province, shortly before 5pm local time on Sunday when their vehicle was caught in an explosion.

Medical treatment was provided before both soldiers were taken to the field hospital at Camp Bastion.

Despite the best efforts of the medical team, both soldiers died as a result of their wounds. Next of kin have been informed.

A Ministry of Defence spokesman said: "It is with much sadness that the Ministry of Defence must confirm that two soldiers serving with 40 Commando Royal Marines have been killed in an explosion on Sunday, 30th March 2008, in southern Afghanistan.

"Just after 1653 local time, the soldiers were conducting a patrol in the vicinity of Kajaki, Helmand Province, when the vehicle they were travelling in was caught in an explosion.

"Next of kin have been informed and there will be a 24 hour period of grace before further details are released."

The International Security Assistance Force said one of the soldiers was pronounced dead on arrival at Camp Bastion and the second died shortly afterwards.

Task Force Helmand spokesperson Lt Col Simon Millar said: "Our thoughts are with the families and loved ones of the soldiers who have been killed in this incident."