(CNN) -- Five U.S. soldiers facing murder charges in the deaths of three Afghan civilians earlier this year have now been charged with "conspiracy to commit premeditated murder," and seven more soldiers have been charged in connection with the probe into the incidents.
The five facing murder charges are Pfc. Andrew Holmes of Boise, Idaho; Spc. Adam Winfield of Cape Coral, Florida; Spc. Michael Wagnon of Las Vegas, Nevada; Spc. Jeremy Morlock of Wasilla, Alaska; and Staff Sgt. Calvin Gibbs of Billings, Montana. They are from the 5th Stryker Brigade.
The alleged killings took place at or near Forward Operating Base Ramrod in southern Afghanistan's volatile Kandahar province.
In June, the five were charged with murder. Holmes was accused of killing Afghan civilian Gul Mudin in January with a grenade and rifle. Winfield is accused of killing civilian Mullah Adahdad in May in a similar manner. Wagnon is accused of shooting to death Marach Agha in February.
Morlock and Gibbs each were charged with three counts of murder and one count of assault involving the same victims as in the cases against Holmes, Wagnon and Winfield.
On Wednesday, the military added conspiracy and other additional charges against the five. Morlock, Holmes, and Winfield were charged with wrongfully using a Schedule I controlled substance.
Charges were also filed against seven other soldiers from the 5th Stryker Brigade, the military said Wednesday, but none involve murder or conspiracy to commit murder.
The seven are Staff Sgt. Robert Stevens, Sgt. Darren Jones, Cpl. Emmitt R. Quintal, Staff Sgt. David Bram, Pfc. Ashton A. Moore, Spc. Adam Kelly and Spc. Corey Moore.
All were charged with conspiracy-related and other charges.
Stevens and Ashton Moore were charged with conspiracy to commit aggravated assault with a dangerous weapon.
Jones was charged with conspiracy to commit assault and battery and conspiracy to commt aggravated assault with a dangerous weapon.
Quintal, Bram, Kelly and Corey Moore were charged with conspiracy to commit assault and battery.
Stevens was charged with wrongfully and wantonly engaging in conduct likely to cause death or bodily harm to other soldiers. Jones, Quintal, Bram, Kelley and Corey Moore were charged with unlawfully striking another soldier.