The US soldier accused of killing 16 civilians in Afghanistan earlier this week has been named as Staff Sergeant Robert Bales, a US official said today.

The official, who spoke on condition of anonymity, declined to provide additional details about the soldier, who is believed to have walked off his base in southern Afghanistan on Sunday and gunned down the 16 villagers, plunging already tense US-Afghan relations into a tailspin.

Afghan President Hamid Karzai accused the US earlier today of failing to fully cooperate with an investigation into the massacre.

He also questioned whether more than one soldier was involved given the high death toll in the shootings.

The lawyer defending the unidentified soldier accused of the killings last weekend has said he does not expect his client to be charged for several weeks.

John Henry Browne, a well-known American defence attorney, said he had already talked with his client who was being held at a military base in Kuwait.

Mr Brown said the soldier, who had completed three tours of duty in Iraq, told him he had "not been thrilled" at being sent to Afghanistan.

"He and his family were told that his tours in the Middle East were over. His family was counting on him not being redeployed," Mr Browne said at a news conference in Seattle.

"Literally overnight that changed. So I think it would be fair to say that he and the family were not happy that he was going back."

An unnamed US official told The New York Times the killings were a result of "a combination of stress, alcohol and domestic issues - he just snapped."

Asked about the report, Mr Browne said he did not know about alcohol and acknowledged that stress was a factor, but he dismissed the domestic issue as "nonsense."

Mr Browne said he had not discussed details of the incident with his client but added that the man's unit had sustained casualties about the time of the civilian killings.

"I don't know if I'd call them friends, but other people deployed in that base were seriously injured and/or killed shortly before these allegations," he said.

Mr Browne would not go into specifics about the identity or well-being of his client. He said only that he was originally from the US midwest and was at the moment "more shocked than anything."

12 Turkish soldiers killed in Afghan crash

Twelve Turkish soldiers have been killed in a helicopter crash in the Afghan capital of Kabul.

The NATO helicopter crashed into a house on the outskirts of the city killing four Aghan civilians.

Turkey's foreign minister said the cause of the crash was apparently a technical fault.

Meanwhile, the US military has said that a top US commander in Afghanistan, Major General Mark Gurganus, was the target of an attack at a NATO base this week.

Maj Gen Gurganus and his deputy were part of a VIP delegation assembled to greet Defense Secretary Leon Panetta, as he arrived by plane at British-run Camp Bastion in Helmand province.

In an apparent suicide attack, an Afghan translator drove a stolen vehicle onto the runway ramp.

After having downplayed the incident, officials said Wednesday's incident was much more serious than initial accounts suggested.

Officials said that the attacker was only minutes away from striking the area where Mr Panetta's aircraft was due to park.

The attacker set himself on fire, apparently in a failed attempt to detonate the car, and later died from his burns.