Authorities have said the Iraqi men were bound, blindfolded, shot in the head and dumped in a Baghdad canal around April 2007 in retribution for casualties within the 1st Battalion, 18th Infantry Regiment. The soldiers are currently part of the 172nd Infantry Brigade.
The Army said in a statement released Wednesday that Sgt. John E. Hatley, 40; Sgt. 1st Class Joseph P. Mayo, 27; and Sgt. Michael P. Leahy Jr., 26 - all formerly assigned to 1st Battalion, 18th Infantry Regiment - faced charges of premeditated murder, conspiracy to commit premeditated murder and obstruction of justice. The hometowns of the men were not disclosed, citing privacy.
Additionally, Hatley and Leahy were also charged with one count each of premeditated murder and conspiracy to commit premeditated murder for a separate incident that happened near Baghdad in January 2007. Leahy was also charged with being an accessory after the fact, the statement said.
The Army did not provide details of that incident.
The men are still assigned to their current unit and will face an Article 32 hearing, which has not been scheduled, said Lt. Col. Eric Bloom, a public affairs officer with the Joint Multinational Training Command in Grafenwoeher, Germany.
An Article 32 hearing is equivalent to a civilian preliminary hearing to determine whether there is sufficient evidence for a court-martial.
Two other American soldiers have already been charged in the April incident.
Spc. Belmor Ramos, 23, and Spc. Steven Ribordy, 25 - also of the 172nd Infantry Brigade - were charged with conspiracy to commit premeditated murder last week. Ribordy was also charged with being an accessory after the fact.
Ramos' court-martial is scheduled for Thursday in Vilseck, Germany. A court-martial for Ribordy has not yet been scheduled. Both men waived their right to an Article 32 hearing.
Staff Sgt. Jess Cunningham and Sgt. Charles Quigley, are also accused of participating in the murders. Cunningham and Quigley appeared at an Article 32 hearing in August. So far, no decision has yet been made whether they should be charged.
The Army said the allegations facing the men related to "the deaths of several detainees who were captured as part of combat operations last year."
A statement, released in January, said that "preliminary findings indicate the deceased detainees were not persons detained in a detention facility," indicating the men were killed shortly after being captured.
In other developments: