US Edition Special Forces made a series of night jumps on the outskirts of Baghdad in a campaign against insurgent leaders and bomb-making factories, The Daily Telegraph has learnt.
The operations - which can only now be disclosed - played a significant role in removing "high value targets'' and reducing the ability of insurgents to make roadside bombs.
On at least a dozen occasions, SAS soldiers using highly-manoeuvrable parachutes jumped from the back of a Hercules aircraft at medium altitude. After steering for several miles, they landed close to insurgent strongholds.
The troops carried out operations that included setting up an observation post using electronic devices to spy on insurgents.
Dressed in the SAS's latest combat uniforms, with some carrying the powerful Heckler and Koch 417 rifle mounted with silencers, the men also assisted SAS helicopter-borne troops or mounted raids themselves.
"It was the surprise factor that we were after,'' said a Special Forces soldier involved in the operations.
Using special chest rigs mounted with satellite navigation, radios, altimeters and oxygen masks, the soldiers at first gathered in the sky and then steered towards the ground as a group.
"These jumps took place all over the city but particularly Sadr city on the eastern edge of Baghdad. You would land on the outskirts, on the right side of the Tigris, and then tab in. [Tab is an Army acronym for tactical advance to battle].
"It gives you the ability of surprise for a hard knock [assault operation] or to get to that point where you have eyes on the target without anyone having a clue that you are in there. As soon as you put a helicopter up, people know what's going on.''
On some occasions a helicopter force was called in to start an operation, otherwise they were used to extract the soldiers.
"We had the means to get into a building and means to fight our way out,'' the soldier said. "We did arrests. We are not going in to neutralise everything but to try to capture targets. However, if you are in the course of apprehending somebody and your life is under threat, if somebody is pointing a gun at you then they will be very lucky to survive.''
News of the combat jumps, which were made over the past two years, comes at a time when a shortage of RAF Hercules and pilots has meant that a third of the 2,400 paratroopers in 16 Air Assault Brigade are not qualified to jump.
A few parachute jumps were used by the SAS and SBS in Afghanistan in 2001.
Parachuting is made difficult in the combat zones by the high altitude and rough terrain.