The Taliban has executed scores of Afghan security force members after they surrendered, Human Rights Watch said.
The shootings were most common in Helmand province, in the south of the country, where the Taliban has strong control, the report says.
Commanders encourage the firing on those trying to surrender or return to Kabul, it said.
“The Taliban controls nearly half of Afghanistan’s provinces, so they regularly target government security forces and officials who defend them,” HRW said.
The organisation quotes civilians who have witnessed the shootings and military personnel who have been captured by the Taliban as saying security forces are usually executed within 10 to 15 minutes of surrendering.
Human Rights Watch also says prisoners are illegally held in “some of the most poorly managed and overcrowded prisons in the country”.
“The Taliban routinely targets Afghan civilians – including aid workers, government employees, and police and soldiers – for revenge, but putting civilians in prison for alleged crimes committed by Taliban fighters is a particularly serious matter,” Sarah Leah Whitson, Middle East director at Human Rights Watch, said.
The Taliban has so far been unsuccessful in re-establishing control over any provinces.