Murder, torture, illegal taxes, theft and the gang rape of a teenage boy are among the abuses by government-backed militias, and the NATO-funded Afghan local police, documented in the 102-page report, “Just Don’t Call It a Militia.”

The groups were formed in response to Afghanistan’s downward security spiral, aiming to capitalise on a basic instinct to protect local communities — much like Iraq’s Awakening Council that helped turn the tide of the Iraq war.

But a lack of training, vetting, oversight and accountability means armed groups are adding another worry to the lives of ordinary Afghans already struggling with a war that this year has claimed a record number of civilian lives.

“Kabul and Washington need to make a clean break from supporting abusive and destabilising militias to have any hope of a viable, long-term security strategy,” said Brad Adams, Asia director at Human Rights Watch.

“Poor governance, corruption, human rights abuses, and impunity for government-affiliated forces all are drivers of the insurgency.”