'IED likely cause of explosion'
7 March 2012 Last updated at 09:27 GMT
Six UK soldiers are missing, believed killed, in southern Afghanistan, the Ministry of Defence has said.
Five from the 3rd Battalion the Yorkshire Regiment and one from the 1st Battalion The Duke of Lancaster's Regiment were on patrol on Tuesday when their vehicle was hit by an explosion.
The families of the soldiers have been informed.
The BBC's Quentin Sommerville is in Lashkar Gah.