SYDNEY — Australian special forces soldiers, mainly from the elite Special Air Service (SAS) regiment, executed 39 prisoners, farmers and other civilians during the Afghanistan war, the chief of the Australian defense forces, Gen. Angus Campbell, said Thursday.

Gen. Campbell said a culture of “toxic competitiveness” that took hold of the SAS and another unit, the Second Commando Regiment, fueled a breakdown in discipline that led to the extrajudicial killings. The abuses included a practice of “blooding” where new soldiers who had never killed anyone in combat were pressured to execute prisoners.

Some of the Afghans killed by 19 Australian soldiers were “adolescent men,” he said. None of the killings took place during the heat of battle.

The incidents, between 2006 and 2013, were disclosed in a heavily redacted report by the military’s inspector general released on Thursday after a four-year investigation.

The allegations were greeted with shock in Australia, which joined the U.S.-led campaign in Afghanistan shortly after the terrorist attacks against the United States on Sept. 11, 2001.

The SAS, which is equivalent to the U.S. Army’s Delta Force, is the most prestigious unit of the Australian Army.

Advertising

Military investigators found that a small but influential group of its soldiers consciously put aside the rules of war and adopted a “self-centered warrior culture” that led to prisoners being killed and radios and weapons being planted on the victims’ bodies. Those who opposed these soldiers were intimidated into silence, which prevented reports from reaching commanders.

“The report notes that the distorted culture was embraced and amplified by some experienced, charismatic and influential noncommissioned officers and their protégés who sought to fuse military excellence with ego, elitism and entitlement,” Gen. Campbell said at a news conference in the capital, Canberra.

“We are a nation that stands up when something goes wrong and deals with it, and that’s what I intend to be part of.”

Afghanistan’s presidential office said on Twitter ahead of the report’s release that Australian Prime Minister Scott Morrison had spoken by telephone with Afghan President Ashraf Ghani to express regret over the abuses and to promise that justice would be served. Australia’s Foreign Ministry had sent a letter of apology for the actions of Australian forces, it added.

Gen. Campbell was in charge of Australian forces in the Middle East during part of the time the unlawful killings took place. The actions came to light when some soldiers told journalists stories of alleged war crimes, which some experts initially greeted with skepticism.

A special unit has been established by the government to amass evidence and prosecute the soldiers, some of whom still work in the army. The families of Afghan victims will be offered compensation, Gen. Campbell said.

An SAS unit, the 2nd squadron, will be abolished and its name retired, he said. Governor-General David Hurley, the country’s ceremonial leader, will be asked to revoke a meritorious unit citation awarded to Australia’s special operations task force in Afghanistan between 2007 and 2014, he added.