US soldier Jeremy Morlock pleaded guilty on Wednesday to three counts of murder of Afghan civilians.

Morlock, 23 admitted in a military court to being part of a “kill team” who deliberately murdered Afghan civilians for “sport” last year.

He also implicated four other members of his infantry unit also charged with killing unarmed Afghan civilians, and agreed to testify against them.

An Army Specialist, Morlock told how he and others in his unit used grenade blasts and rifle fire to kill the civilians and make their deaths look like they had arisen in legitimate combat situations.

The murders took place between January and May last year.

The case follows the publishing by German magazine Der Spiegel this week of shocking photographs that showed Morlock and other American soldiers posing with the dead body of a young Afghan boy.

These atrocities are believed to be the worst to be committed by US troops since they began occupying Afghanistan nearly ten years ago and have drawn comparisons to the abuse of Iraqis at Abu Ghraib prison by US soldiers in 2004.

Morlock who hails from from Sarah Palin’s home town of Wasilla, Alaska now face 24 years in jail but could be out sooner after striking a plea bargain to testify against his fellow soldiers.

In a statement he apologised to the victims’ families and the Afghan people:

“I publicly take responsibility for the deaths,” he said. “I’ve spent a lot of time reflecting on how I lost my moral compass.”