The men are said to have shot their victims ..........
The men are said to have shot their victims and then tried to cover their tracks by making it look like an attack was imminent.
Corporal Jeremy Morlock, 22, is among five members of the 5th Stryker Brigade who are charged with premeditated murder and conspiracy.
If found guilty of all the charges against him, he could face the death penalty.
Prosecutors also allege that members of the platoon mutilated Afghan corpses and even collected fingers and other body parts, and that some posed for photos with bodies.
Morlock's lawyers say his statements were made under the influence of drugs
As the case began at Joint Base Lewis-McChord near Tacoma, Washington, a video of Morlock being interviewed by investigators was shown on US television.
In it he blamed his squad leader, Sergeant Calvin Gibbs, for the killings.
The other three suspected of involvement in the "death squad' are Specialist Adam Winfield, Specialist Michael Wagnon II and Private Andrew Holmes.
Morlock claimed Gibbs - the highest ranking soldier accused - planned "scenarios" during which they could kill civilians.
For example, Morlock said, if they came across someone in a village that had previously been flagged as having Taliban influence, they could throw a grenade at the civilian and claim they had been responding to a threat.
Morlock said: "He (Gibbs) just really doesn’t have any problems with ....killing these people. And so we identify a guy, Gibbs makes a comment, like, you know, you guys wanna wax this guy or what?
"He pulled out one of his grenades, an American grenade, you know, popped it, throws it, tells me where to go to whack this guy, kill this guy, kill this guy."
He claimed Gibbs carried a Russian grenade to leave next to the body to make it look like the soldiers were under attack.
He added: "Gibbs had pure hatred for all Afghanis and constantly referred to them as savages.
"Sometime after Christmas 2009, Gibbs gave me a (fragmentation) grenade and told me that if the situation presented itself that we should go ahead and run with the grenade scenario that he had briefed to us."