Kurdish security forces in Erbil are continuing to torture children to confess their involvement with Islamic State, according to allegations in a report released by Human Rights Watch.

According to the organisation, which first raised the alarm about the mistreatment of child detainees by Kurdish security forces nearly two years ago, it has collected claims of the continued regular use of beatings and electric shocks to extract confessions, often prior to trials lasting a handful of minutes.

The boys interviewed by the group allege the abuse took place in a detention centre in the Iraqi Kurdistan city in 2017 and 2018, where they were being held without access to a lawyer and without being permitted to read the confessions they say security officers wrote and forced them to sign.

The report, published on Tuesday, is based on interviews late last year with 20 boys, aged between 14 and 17, who have been either charged or convicted because of their alleged affiliation with Isis and are being held at the Women and Children’s Reformatory in Erbil.

The group also interviewed three boys who had recently been released.

At the time of the visit by HRW researchers, 63 children were being held at the facility for alleged terrorism-related offences, including 43 who had been convicted.

Sixteen of the 23 children who were interviewed said that security officers known as Asayish officers had beaten them with plastic pipes, electric cables or rods, while three others said the officers had used electric shocks.

Others described being tied into a painful stress position called the “scorpion” for up to two hours. Several boys said the torture continued over consecutive days, and only ended when they confessed.

Four other boys said Asayish threatened them with torture during interrogation. “If you don’t tell us the truth, I will call the guys and they will beat you and break your bones,” a 17-year-old boy recalled his interrogator telling him.

Boys in the yard of the Women and Children’s Reformatory in Erbil, Kurdistan Region of Iraq Photograph: Human Rights Watch

While several of those interviewed said they had joined and worked with Isis, or received religious or military training, only one said that he had participated in fighting against Iraqi military forces.

Others, however, insisted that they had no personal involvement, while admitting family members were involved.

All but one of the boys interviewed said they eventually confessed.

“My confession says that I joined Isis for 16 days, but actually, I didn’t join at all,” one 16-year-old boy told researchers. “I said 16 days to stop the torture.”

Another 14-year-old boy told a similar story.

“First they said I should say I was with Isis, so I agreed,” he said. “Then they told me I had to say I worked for Isis for three months. I told them I was not part of Isis, but they said, ‘No, you have to say it.’” He said that after two hours of interrogation and torture, he agreed.

At least five boys said they told an investigative or trial judge that their confession was produced under torture, but that the judges appeared to ignore their statements.

Most of the children interviewed said they were arrested at checkpoints entering the Kurdistan region, often because their name was on a security list of Isis suspects, while others were arrested at camps for internally displaced people. Many boys believed their name appeared on a security list because a family member was affiliated with Isis, their name was similar to that of another suspect, or people from their village had reported their family because of unrelated grievances.

“Samir”, whose real name, like those of other boys interviewed, has been withheld by HRW to protect his identity, said that like many others he had been arrested by military forces at a checkpoint.

“There were three officers. They bound my hands behind my back, one from above and one below. They beat me with a stick and they gave me five to 10 electric shocks. They put the pads on my left shoulder and on my stomach.

“And while they gave me the shocks, they were beating me with a rod. They did this three days in a row. I was in the room for hours, with them coming in and out and taking breaks. On the third day I confessed. They said to admit to two months with Isis. I did, but it was a lie. I was never with Isis.”

The Kurdistan regional government, which has promised in the past to investigate claims of mistreatment, denied the allegations of torture.

A spokesman for the KRG rejected the HRW report. “The KRG fully disagrees with the accusation of torture of children Isis detainees,” Dindar Zebari, the region’s coordinator for international advocacy, said in a press statement. “We have to rehabilitate them, this is the policy of the KRG.”

Jo Becker, children’s rights advocacy director at HRW, said: “Nearly two years after the Kurdistan regional government promised to investigate the torture of child detainees, it is still occurring with alarming frequency.

“The Kurdistan authorities should immediately end all torture of child detainees and investigate those responsible.”