Both were killed on Tuesday, one in a firefight with the Taliban, the other in an explosion while checking for mines.

The deaths take to 108 the number of British service personnel who have lost their lives since the start of operations in Afghanistan in November 2001.

A soldier from 2nd Battalion the Parachute Regiment died during an exchange of fire with the insurgents in Helmand province.

The other incident came later when a soldier from the regiment's 4th Battalion, attached to 2nd Battalion, got out of a vehicle in the Upper Sangin Valley to check for mines.

This was in support of the same operation, although they were separate incidents, the Ministry of Defence (MoD) said.

The soldier was killed by a suspected improvised explosive device, or roadside bomb.

Last week, four soldiers were killed when a similar bomb ripped through their vehicle. Corporal Sarah Bryant, 26, of the Intelligence Corps, the first British woman to die on active service in Afghanistan, was among the casualties.

Meanwhile, the MoD has unveiled a state-of-the-art machine to help treat wounded troops in the field. The new Apheresis machine separates blood, allowing the removal of platelets which help clotting.

These platelets can be used to treat soldiers who have been injured while the rest of the blood can be returned to its donor. Two of the machines have already been used to treat at least three injured personnel, the MoD said.