|Staff Sergeant Bales is accused of killing 17 Afghan civilians in Kandahar province [US military newsletter]
US soldier Robert Bales has been charged with 17 counts of premeditated murder over the pre-dawn massacre of Afghan villagers earlier this month.
Friday's charges constitute a capital offence which could see Bales facing the death penalty if found guilty.
Bales was officially informed of the total 29 charges against him - including six counts of attempted murder and six counts of aggravated assault and other violations of military law for the wounding of six others - just before noon local time at the US military prison at Fort Leavenworth, Kansas, where he has been confined.
The decision to charge Bales, accused of walking off a US military base with his 9mm pistol and an M-4 rifle outfitted with a grenade launcher, with premeditated murder suggests prosecutors plan to argue he consciously conceived the killings.
An ISAF military legal official, speaking on condition of anonymity, noted that premeditated murder is not something that has to have been contemplated far in advance.
Legal experts have said the death penalty would be unlikely in the case.
The military hasn't executed a service member since 1961 when an Army ammunition handler was hanged for raping an 11-year-old girl in Austria. None of the six men currently on death row at Fort Leavenworth, where Bales is currently detained, was convicted for atrocities against foreign civilians.
The killings -mostly of women and children -are believed to be the deadliest war crime by a NATO soldier during the decade-long war.
The maximum punishment for a premeditated murder conviction is death, dishonorable discharge from the armed forces, reduction to the lowest enlisted grade and total forfeiture of pay and allowances, Colonel Gary Kolb, an ISAF spokesperson said.
The mandatory minimum sentence is life imprisonment with the chance of parole.
A senior US official said earlier that it had "pretty much been decided" the trial would be held in the United States.
The next procedural step will be for an investigating officer to submit a written report on the sufficiency of charges and evidence against Bale. The contents of this report will aid the court in deciding how to address the charges.
Earlier on Friday, the news of Bales' then impending charges prompted dismay in Afghanistan, where a relative of many of those killed in the massacre called for Bales to be tried in the country.
Haji Samad, an elder whose family members were among those killed, said: "We want the prosecution of this American soldier in Afghanistan not in the US, because he committed the crime in Afghanistan.
"Why he is going to be prosecuted in the US? If this man is prosecuted in Afghanistan, we will be relieved. If he is prosecuted in the US, we will be angry and it will remain a pain in our hearts."
A Taliban spokesman said the group had no faith in any trial planned for the accused soldier, and called for revenge against US forces working in the country.
"This was a planned activity and we will certainly take revenge on all American forces in Afghanistan and don't trust such trials," Zabihullah Mujahid, the spokesman, told Reuters by telephone.
He reiterated claims held by many Afghans that there must have been more than one soldier involved in the massacre, claims US authorities have consistently denied.
'Cleverness and deception'
"Now America tries to deceive the people and tries to blame the act on one soldier. This is a crime by the American
government. Using such cleverness and deception is a huge crime," Mujahid said.
Al Jazeera's James Bays, reporting from Kabul, said: "[The Taliban say] they don't feel that there will be a fair trial in the United States.
"I think they are looking at some of the comments that have come through in the press, talking about the background to this - why the soldier may have been pushed over the edge, why he may have carried out these killings.
"If you speak to ordinary Afghans they will tell you that there are no such explanations given when someone joins the Taliban and, many times, there are traumatic events that drive people to join the Taliban too," Bays added.
Bales is charged with the killings of civilians in two villages near his southern Afghanistan military post in the early hours of March 11.
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The attorney representing Bales, John Henry Browne, said in an appearance on American television that his client has memory gaps of the pre-dawn attack in the homes of villagers in southern Afghanistan.
Bales was "kind of in shock ... he didn't really know the nature of the specific allegations when I met with him" Browne said in a Friday morning interview with the CBS network.
The Seattle-based attorney said of the impending case itself, "my first reaction to all of this is, prove it ... This is
going to be a very difficult case for the government to prove in my opinion. There is no CSI (crime scene investigation) stuff. There's no DNA. There's no fingerprints."
Military authorities had originally said Bales was suspected of killing 16 Afghan villagers, nine children and seven adults. Six of those killed belonged to one family; they included five daughters of Mohamed Wazir, named Masooma, Farida, Palwasha, Nabia and Esmatullah. Wazir's son Faizullah was also killed.
Authorities changed the death toll to 17 on Thursday, raising the number of adults by one but without explaining how the change came about.
It is possible some of the dead were buried before US military officials arrived at the scene of the carnage. Bales, 38, also allegedly burned some of his victims' bodies before returning to his base and surrendering.
The charges are to be read to Bales on Friday at the military prison at Fort Leavenworth in Kansas where he has been held since being flown from Afghanistan last week. He faces trial under military law, but it could be months before any public hearing.