It was early last October that Kasim Mehaddi Hilas says he witnessed the rape of a boy prisoner aged about 15 in the notorious Abu Ghraib prison in Iraq. “The kid was hurting very bad and they covered all the doors with sheets,” he said in a statement given to investigators probing prisoner abuse in Abu Ghraib. “Then, when I heard the screaming I climbed the door … and I saw [the soldier’s name is deleted] who was wearing a military uniform.” Hilas, who was himself threatened with being sexually assaulted in Abu Graib, then describes in horrific detail how the soldier raped “the little kid”.

In another witness statement, passed to the Sunday Herald, former prisoner Thaar Salman Dawod said: “[I saw] two boys naked and they were cuffed together face to face and [a US soldier] was beating them and a group of guards were watching and taking pictures and there was three female soldiers laughing at the prisoners. The prisoners, two of them, were young.”

It’s not certain exactly how many children are being held by coalition forces in Iraq, but a Sunday Herald investigation suggests there are up to 107. Their names are not known, nor is where they are being kept, how long they will be held or what has happened to them during their detention.

Proof of the widespread arrest and detention of children in Iraq by US and UK forces is contained in an internal Unicef report written in June. The report has – surprisingly – not been made public. A key section on child protection, headed “Children in Conflict with the Law or with Coalition Forces”, reads: “In July and August 2003, several meetings were conducted with CPA (Coalition Provisional Authority) … and Ministry of Justice to address issues related to juvenile justice and the situation of children detained by the coalition forces … Unicef is working through a variety of channels to try and learn more about conditions for children who are imprisoned or detained, and to ensure that their rights are respected.”

Another section reads: “Information on the number, age, gender and conditions of incarceration is limited. In Basra and Karbala children arrested for alleged activities targeting the occupying forces are reported to be routinely transferred to an internee facility in Um Qasr. The categorisation of these children as ‘internees’ is worrying since it implies indefinite holding without contact with family, expectation of trial or due process.”

The report also states: “A detention centre for children was established in Baghdad, where according to ICRC (International Committee of the Red Cross) a significant number of children were detained. Unicef was informed that the coalition forces were planning to transfer all children in adult facilities to this ‘specialised’ child detention centre. In July 2003, Unicef requested a visit to the centre but access was denied. Poor security in the area of the detention centre has prevented visits by independent observers like the ICRC since last December.

“The perceived unjust detention of Iraqi males, including youths, for suspected activities against the occupying forces has become one of the leading causes for the mounting frustration among Iraqi youths and the potential for radicalisation of this population group.”

Journalists in Germany have also been investigating the detention and abuse of children in Iraq. One reporter, Thomas Reutter of the TV programme Report Mainz, interviewed a US army sergeant called Samuel Provance, who is banned from speaking about his six months stationed in Abu Ghraib but told Reutter of how one 16-year-old Iraqi boy was arrested.

“He was terribly afraid,” Provance said. “He had the skinniest arms I’ve ever seen. He was trembling all over. His wrists were so thin we couldn’t even put handcuffs on him. Right when I saw him for the first time, and took him for interrogation, I felt sorry for him.

“The interrogation specialists poured water over him and put him into a car. Then they drove with him through the night, and at that time it was very, very cold. Then they smeared him with mud and showed him to his father, who was also in custody. They had tried out other interrogation methods on him, but he wasn’t to be brought to talk. The interrogation specialists told me, after the father had seen his son in this state, his heart broke. He wept and promised to tell them everything they wanted to know.”

An Iraqi TV reporter Suhaib Badr-Addin al-Baz saw the Abu Ghraib children’s wing when he was arrested by Americans while making a documentary. He spent 74 days in Abu Ghraib.

“I saw a camp for children there,” he said. “Boys, under the age of puberty. There were certainly hundreds of children in this camp.” Al-Baz said he heard a 12-year-old girl crying. Her brother was also held in the jail. One night guards came into her cell. “She was beaten,” said al-Baz. “I heard her call out, ‘They have undressed me. They have poured water over me.’”

He says he heard her cries and whimpering daily – this, in turn, caused other prisoners to cry as they listened to her. Al-Baz also told of an ill 15-year-old boy who was soaked repeatedly with hoses until he collapsed. Guards then brought in the child’s father with a hood over his head. The boy collapsed again.

Although most of the children are held in US custody, the Sunday Herald has established that some are held by the British Army. British soldiers tend to arrest children in towns like Basra, which are under UK control, then hand the youngsters over to the Americans who interrogate them and detain them.

Between January and May this year the Red Cross registered a total of 107 juveniles in detention during 19 visits to six coalition prisons. The aid organisation’s Rana Sidani said they had no complete information about the ages of those detained, or how they had been treated. The deteriorating security situation has prevented the Red Cross visiting all detention centres.

Amnesty International is outraged by the detention of children. It is aware of “numerous human rights violations against Iraqi juveniles, including detentions, torture and ill-treatment, and killings”. Amnesty has interviewed former detainees who say they’ve seen boys as young as 10 in Abu Ghraib.

The organisation’s leaders have called on the coalition governments to give concrete information on how old the children are, how many are detained, why and where they are being held, and in what circumstances they are being detained. They also want to know if the children have been tortured.

Alistair Hodgett, media director of Amnesty International USA, said the coalition forces needed to be “transparent” about their policy of child detentions, adding: “Secrecy is one thing that rings alarm bells.” Amnesty was given brief access to one jail in Mosul, he said, but has been repeatedly turned away from all others. He pointed out that even countries “which don’t have good records”, such as Libya, gave Amnesty access to prisons. “Denying access just fuels the rumour mill,” he said.

Hodgett added that British and US troops should not be detaining any Iraqis – let alone children – following the recent handover of power. “They should all be held by Iraqi authorities,” he said. “When the coalition handed over Saddam they should have handed over the other 3000 detainees.”

The British Ministry of Defence confirmed UK forces had handed over prisoners to US troops, but a spokes man said he did not know the ages of any detainees given to the Americans.

The MoD also admitted it was currently holding one prisoner aged under 18 at Shaibah prison near Um Qasr. Since the invasion Britain has detained, and later released, 65 under-18s. The MoD claimed the ICRC had access to British jails and detainee lists.

High-placed officials in the Pentagon and Centcom told the Sunday Herald that children as young as 14 were being held by US forces. “We do have juveniles detained,” a source said. “They have been detained as they are deemed to be a threat or because they have acted against the coalition or Iraqis.”

Officially, the Pentagon says it is holding “around 60 juvenile detainees primarily aged 16 and 17”, although when it was pointed out that the Red Cross estimate is substantially higher, a source admitted “numbers may have gone up, we might have detained more kids”.

Officials would not comment about children under the age of 16 being held prisoner. Sources said: ‘‘It’s a real challenge ascertaining their ages. Unlike the UK or the US, they don’t have IDs or birth certificates.” The Sunday Herald has been told, however, that at least five children aged under 16 are being kept at Abu Ghraib and Camp Bucca.

A highly placed source in the Pentagon said: “We have done investigations into accusations of juveniles being abused and raped and can’t find anything that resembles that.”

The Pentagon’s official policy is to segregate juvenile prisoners from the rest of the prison population, and allow young inmates to join family members also being detained. “Our main concern is that they are not abused or harassed by older detainees. We know they need special treatment,” an official said.

Pentagon sources said they were unaware how long child prisoners were kept in jail but said their cases were reviewed every 90 days. The last review was early last month. The sources confirmed the children had been questioned and interrogated when initially detained, but could not say whether this was “an adult-style interrogation”.

The Norwegian government, which is part of the “coalition of the willing”, has already said it will tell the US that the alleged torture of children is intolerable. Odd Jostein Sæter, parliamentary secretary at the Norwegian prime minister’s office, said: “Such assaults are unacceptable. It is against international laws and it is also unacceptable from a moral point of view. This is why we react strongly … We are addressing this in a very severe and direct way and present concrete demands. This is damaging the struggle for democracy and human rights in Iraq.”

In Denmark, which is also in the coalition, Save the Children called on its government to tell the occupying forces to order the immediate release of child detainees. Neals Hurdal, head of the Danish Save the Children, said the y had heard rumours of children in Basra being maltreated in custody since May.

Human Rights Watch (HRW) said it was “extremely disturbed” that the coalition was holding children for long periods in jails notorious for torture. HRW also criticised the policy of categorising children as “security detainees”, saying this did not give carte blanche for them to be held indefinitely. HRW said if there was evidence the children had committed crimes then they should be tried in Iraqi courts, otherwise they should be returned to their families.

Unicef is “profoundly disturbed” by reports of children being abused in coalition jails. Alexandra Yuster, Unicef’s senior adviser on child detention, said that under international law children should be detained only as a last resort and only then for the shortest possible time.

They should have access to lawyers and their families, be kept safe, healthy, educated, well-fed and not be subjected to any form of mental or physical punishment, she added. Unicef is now “desperately” trying to get more information on the fate of the children currently detained in coalition jails.