The report documents 29 cases in northern Iraq that show how children under the age of 15 are being forced to become child soldiers for PKK-affiliated terror groups.
"There was a rule that if you were under 18 you could not fight … But the fighters don't care about the rules," a 16-year-old Yazidi boy said of the two years he fought alongside PKK-affiliated groups in Iraq and Syria.
The boy said he was recruited by the HPG, a group aligned with the PKK, when he was living in a camp for internally displaced people in the Kurdistan region of northern Iraq.
For two years, he fought in different areas of northern Iraq and in neighbouring Syria.
In that time, he told researchers at the Human Rights Watch (HRW), he witnessed "many" other children engaged in the fighting.
Though he eventually left the HPG forces, HRW says the boy is indicative of an alarming trend among PKK-linked groups in Iraq.
According to their newly published investigation, armed groups in Iraq have repeatedly recruited and trained child soldiers in the last three years.
In a statement released on Thursday, the not-for-profit New York-based rights group has accused forces affiliated with the armed wing of the PKK – which Turkey, the United States and the European Union classify as a terrorist group – of recruiting boys and girls as young as nine to fight in northern Iraq.
Calling on the PKK to "categorically denounce" the use of child soldiers, Zama Coursen-Neff, the children's rights director at Human Rights Watch, said, "Boys and girls should be with their families and going to school, not used as means to military ends."
"A drop in the bucket"
The HRW investigation documented 29 cases of Kurdish and Yazidi children recruited by the HPG and the YBS to fight against the terrorist group Daesh in northern Iraq. Both groups are affiliated with the PKK.
Speaking to TRT World, Belkis Wille, an Iraqi senior researcher in the Middle East and North Africa division of HRW, said the organisation conducted their research in August and September, but that they found evidence of child recruitment dating back to at least 2013.
"Our research is [just] a drop in the bucket," Wille said, referring to the likelihood that the actual amount of child recruitment is much greater than the 29 cases HRW was able to uncover.
"The children we spoke to said there were many, many, many other children with them" on the battlefield, Wille said.
Though not all of the children were involved in active combat, some staffed checkpoints and prepared weapons for battle. HRW says any use of children under the age of 18 constitutes a war crime.
With the publication of their findings, the organisation hopes to pressure the PKK and its affiliates to put an end to the use of child combatants.
There are worries that the PKK's status as a non-state actor – they established a paramilitary force in 1984 – makes it more difficult for rights groups to put pressure on them.
However, Wille said that in the case of the PKK, the fact that they are a non-state actor may actually work to the advantage of rights groups, including HRW.
"These sorts of allegations, especially when it comes from local communities that the PKK wants to engage, can be quite damaging to their image," Wille said.
In particular, Wille said rights groups and activists can use the PKK's need to be seen as a legitimate force fighting for the rights of the Kurdish people, and not only an armed insurgency, as a means of putting pressure on them:
"They want to sit at international tables with governments whose support they are looking for, but things like the use of child soldiers will keep them from being taken seriously at these tables."
Last year, the YPG, a Syria-based offshoot of the PKK, pledged to disarm more than 100 fighters under the age of 18. However, in July, HRW accused the YPG of backtracking on their pledge and once again arming children as young as 14 to fight Daesh.
The practise of employing child soldiers is not a new phenomenon in Iraq.
In the 1990s, the government of former Iraqi President Saddam Hussein was accused of establishing three-week camps where boys as young as ten were trained on the use of small arms and practised military-style drills.
The cadre of Iraqi boys, estimated to number in the thousands, was popularly referred to as the Ashbal Saddam, or Saddam's Lion Cubs.
Further, the PKK is not the only armed group to be accused of using child soldiers in the region.
Daesh forces have repeatedly published propaganda material featuring Iraqi, Syrian and Libyan children posing next to their group's black-and-white flag. In 2015, the group released a video in which a young boy was among the fighters leading a Palestinian man to his execution.
Leaked documents confirm that the indoctrination and training of children is actively encouraged within the armed group.
Earlier this year, Turkish authorities, including President Recep Tayyip Erdogan, said that a Daesh-claimed bombing targeting a Kurdish wedding in the southern province of Gaziantep was carried out by a child suicide bomber.
Wedding guests speaking to TRT World last August said an adolescent boy had been made to transport a baby carriage containing a bomb into the crowd.
Daesh and PKK
Though both the PKK and Daesh have been accused of recruiting child combatants, Wille, the HRW researcher, said she noticed one glaring difference between PKK and Daesh when it came to the recruitment of children.
PKK recruitment, Wille said, was largely voluntary.
The children recruited by the PKK, she said, saw taking up arms as a way to "fight back" against the abuses inflicted upon them by Daesh.
In some instances, Wille said children were encouraged by their parents, who supported the PKK, to join, but that the children ultimately decided for themselves.
However, many of the children HRW spoke to, she said, were deeply traumatised and disillusioned by what they saw on the battlefields.
By contrast, Wille said nearly all of the Daesh recruitment was forcible. Daesh has been called the "worst offender" of child recruitment by the United Nations and international rights groups.
According to the Syrian Observatory for Human Rights, a London-based rights monitor, in 2015 at least 52 children under the age of 16 were killed while fighting for Daesh in Syria.
Unlike the PKK, Wille said pressuring Daesh will prove more difficult.
"Daesh isn't looking for public or political legitimacy, so it's more difficult to put serious pressure on them."