WASHINGTON (NYTIMES) - None of the military personnel involved in a botched drone strike in Kabul, Afghanistan, that killed 10 civilians will face any kind of punishment after Defence Secretary Lloyd Austin approved recommendations from two top commanders, a senior Pentagon official said.

The Pentagon acknowledged in September that the last US drone strike before American troops withdrew from Afghanistan was a tragic mistake that killed the civilians, including seven children, after initially saying it had been necessary to prevent an Islamic State attack on troops.

A subsequent high-level investigation into the episode found no violations of law but stopped short of fully exonerating those involved, saying that was "commander business".

Mr Austin left the final word on any administrative action, such as reprimands or demotions, to two senior commanders - General Kenneth McKenzie Jr, head of the military's Central Command, and General Richard Clarke, head of the Special Operations Command. Both officers found no grounds for penalising any of the military personnel involved in the episode, the Pentagon official said. The official spoke on condition of anonymity to discuss delicate personnel matters.

In two decades of war against shadowy enemies like al-Qaeda and the Islamic State group, the US military has killed hundreds, if not thousands, of civilians by accident in war zones like Iraq, Afghanistan, Syria and Somalia. And while the military from time to time accepts responsibility for an errant airstrike or a ground raid that harms civilians, rarely does it ever hold specific individuals accountable.

The most prominent recent exception to this trend happened in 2016, when the Pentagon disciplined at least a dozen military personnel for their roles in an airstrike in October 2015 on a Doctors Without Borders hospital in Kunduz, Afghanistan, that killed 42 people. But none faced criminal charges.

Critics of the Kabul strike pointed to the incongruity of acknowledging the mistake but not finding anyone accountable for any wrongdoing.

"This decision is shocking," said Mr Steven Kwon, founder and president of Nutrition & Education International, the California-based aid organisation that employed Mr Zemari Ahmadi, the driver of a white Toyota sedan that was struck by the US drone. "How can our military wrongly take the lives of 10 precious Afghan people and hold no one accountable in any way?"

The acknowledgement of the mistaken strike came a week after a New York Times investigation of video evidence challenged assertions by the military that it had struck a vehicle carrying explosives meant for Hamid Karzai International Airport.

Public scrutiny into military strikes against shadowy adversaries like the Islamic State group and al-Qaeda that also killed civilians is intensifying. Mr Austin last month ordered a new high-level investigation into a US airstrike in Syria in 2019 that killed dozens of women and children, and that military officials tried to conceal it afterwards.

On Sunday, an investigation by The Times revealed that a top-secret US strike cell launched tens of thousands of bombs and missiles against the Islamic State group in Syria, but in the process of pounding a vicious foe, the commandos sidestepped safeguards and repeatedly killed civilians.The higher-level inquiry into the Kabul strike by the Air Force's inspector general, Lt General Sami Said, blamed a series of erroneous assumptions, made over the course of eight hours as US officials tracked a white Toyota Corolla through the Afghan capital, for causing what he called "confirmation bias", leading to the Aug. 29 attack.

Mr Said, in releasing his findings last month, found no criminal wrongdoing but said any other errors warranting disciplinary action would be up to senior commanders. "You should not perceive the fact that I didn't call any individual out with accountability," he told reporters. "That just does not mean that the chain of command won't." But it did not.

The general's investigation made several recommendations for fixing the process through which strikes are ordered, including putting in new measures to cut down the risk of confirmation bias and reviewing the prestrike procedures used to assess the presence of civilians. Pentagon officials say they are now incorporating those measures into a broader strategy to prevent civilian harm on the battlefield.

Almost everything senior defence officials asserted in the hours, days and weeks after the Kabul drone strike turned out to be false. The explosives the military claimed were loaded in the trunk of a white sedan struck by the drone's Hellfire missile were probably water bottles. A secondary explosion in the courtyard in the densely populated Kabul neighbourhood where the attack took place was probably a propane or gas tank, military officials said.

Ahmadi, the driver of the white sedan that was struck by the US drone, had no ties to the Islamic State group, officials said.

General McKenzie, head of the Central Command, said in a news conference in September that the strike was carried out "in the profound belief" that the Islamic State group was about to launch another attack on the airport.

Since then, the Pentagon has offered unspecified condolence payments to the family of those killed in the drone strike. The Pentagon has also said it is working with the State Department to help surviving members of the family relocate to the United States, but negotiations appear to have bogged down in recent weeks.

"I've been beseeching the US government to evacuate directly impacted family members and NEI employees for months because their security situation is so dire," Mr Kwon said, referring to employees of the aid organisation where Mr Ahmadi worked.

Mr John F. Kirby, the Pentagon's top spokesman, said that Mr Austin wanted to resolve the situation "as soon as possible". "There has been numerous and recent exchanges between us and NEI about trying to get the necessary information in place so that we can affect their safe departure and affect the ex gratia payment," Mr Kirby told reporters last week.

Congress has authorised the Pentagon to pay up to US$3 million (S$4.1 million) a year to compensate for property damage, personal injury or deaths related to the actions of US armed forces, as well as for "hero payments" to the family members of local allied forces, such as Afghan or Iraqi troops fighting al-Qaeda or the Islamic State group.

Condolence payments for deaths caused by the US military have varied widely in recent years. In the 2019 fiscal year, for instance, the Pentagon offered 71 such payments - ranging from US$131 to US$35,000 - in Afghanistan and Iraq.

In an episode the Pentagon acknowledged publicly for the first time to The Times, the military in Afghanistan earlier this year paid US$5,000 to a family there whose child was killed in an airstrike in January.

According to Captain Bill Urban, a spokesperson for the Central Command, this is what happened: On Jan 8, Taliban forces attacked an Afghan security forces' checkpoint in the Shindand district, near Herat. After Afghan troops requested US help, a US drone identified five Taliban fighters armed with small arms and rocket-propelled grenades. Two of the fighters broke away, repositioned and fired grenades at checkpoint.

American troops ordered a strike against the Taliban fighters firing the grenades. The drone operator scanned the target area and after determining it was free of civilians, launched the strike against the Taliban fighters.

However, five seconds before the weapon hit the fighters, the drone operator saw a child approaching the target. Within two seconds, the drone operator tried to abort the strike and veer the weapon away. That failed, and the potential civilian casualty was reported immediately.

An investigation began Jan 9 and confirmed that while a child had been killed in the airstrike, the decision to conduct the strike was made properly, in accordance with the existing rules of engagement.

"We deeply regret the loss of innocent life associated with this strike and continue to strive to avoid such loss in the future," Mr Urban said in a response to questions from The Times about the strike.