Hundreds of children are in adult prisons in north-eastern Syria, the International Committee of the Red Cross said on Wednesday, disclosing their plight for the first time.
The children, mostly boys, have been taken to prisons from Al Hol, a desert camp run by Syrian Kurdish forces for 60,000 people from more than 60 countries, the aid agency said.
Most of the camp's residents are women and children who fled there after ISIS's last enclaves collapsed two years ago. Local authorities say many are associated with the extremist fighters.
"Hundreds of children, mostly boys, some as young as 12, are detained in adult prisons, places they simply do not belong," said Fabrizio Carboni, the Red Cross director for the Middle East.
The organisation made 36 visits to prisons across Syria last year, as the only agency with such access.
It has private talks with inmates on their treatment and conditions, but its confidential findings are shared only with the authorities.
It has access to some prisons in the Kurdish-controlled north-east Syria, a spokeswoman said.
The Red Cross also renewed its appeal for countries to repatriate their nationals from Al Hol and keep families together "as international law requires".
"I really can't get used to seeing so many children behind barbed wire," said Mr Carboni, who has visited Al Hol four times in the past two years.
The Red Cross runs a field hospital and provides food and water at the sprawling site.
Medical needs are huge, with a rise in children dying there last year, including some from preventable conditions, Mr Carboni said.
Unicef said eight children under 5 years of age died at the camp last August, half from malnutrition-related complications.
The other deaths had been caused by dehydration from diarrhoea, heart failure, internal bleeding and hypoglycaemia, the UN children's agency said.
