Washington:
A US soldier will be charged with 17 counts of murder stemming from the killings of civilians in a rampage in southern Afghanistan, a US official said on Thursday.
The official, confirming the murder charges on condition of anonymity, also said Army Staff Sergeant Robert Bales would be charged with six counts of assault and attempted murder.
Mr Bales, 38, is alleged to have walked out of his base in the southern province of Kandahar under cover of darkness on March 11 and killed 17 people in two nearby villages, including women and children, and burning some of their bodies. He later returned to his base and gave himself up.
The charges were raised by the number of deaths reported immediately after the atrocity, which plunged relations between the United States and Afghanistan to their lowest point in a decade of war.
The killings came at an already tense time for US-Afghan ties after the burning of Qurans by Americans, deadly anti-American protests and an earlier video that showed US Marines urinating on the bloodied corpses of Taliban militants.
US officials had pledged a swift and thorough investigation, and US Defense Secretary Leon Panetta has said Bales could face the death penalty if convicted. The soldier's motives remain unknown.
Initially transferred to a US base in Kuwait, Bales was placed on Friday at the Fort Leavenworth military prison in Kansas, where he is being held in an isolation cell.
The charges are due to be officially announced on Friday, sources close to the investigation said.
Under the US military justice system, prosecutors draft charges to be filed against an accused soldier, present them to his unit commander, who must then decide whether there is enough evidence to believe a crime was committed.
Mr Bales is due to appear for an Article 32 preliminary hearing at a still unknown date before he could possibly be sent before a court-martial.
His lawyer John Henry Browne visited his client for the first time on Monday and Tuesday, telling reporters that Bales suffered from amnesia.
"He has an early memory of that evening and he has a later memory... but he doesn't have memory of the evening in between," Browne told
CBS News, adding that his client dismissed reports that he was drunk at the time of the attacks.
The lawyer said he would not put forward an insanity defense in any proceedings, but could pursue the case on the grounds of "diminished capacity" due to an emotional breakdown.
A decorated veteran who did three tours in Iraq before deploying to Afghanistan in December, Mr Bales suffered a traumatic brain injury during a road accident in Iraq.
Mr Browne said last week that Bales had recently been under stress, which was heightened when he witnessed a fellow soldier seriously wounded by stepping on a mine.
The US media reported that Mr Bales, who in addition to Mr Browne also has a military lawyer and his wife were enduring financial problems.
If the defense can convince jurors the attack was not premeditated, the maximum sentence would be life in prison and could include the possibility of parole after ten years.
The goal is "attacking the level of intent," said Daniel Conway, a military defense attorney who is not involved in the case.
A conviction on premeditated murder can result in the death penalty or life in prison without possible parole.
"It makes a world of difference for his client," Conway told Agence France Presse (AFP).
But his lawyers are playing with a double-edged sword by announcing their intentions, Conway said, because investigators will be on alert for any evidence that goes against diminished capacity.
Military juries are also not inclined to put much store in arguments that injuries, post-traumatic stress disorder or financial problems result in diminished capacities, he said.