'War crimes' in Iraq as armed groups recruit children
HRW found 29 cases in northern Iraq where children were being recruited by the People's Defence Forces (HPG) and the Shingal Resistance Units (YBS), groups known to be linked to the PKK.
"The PKK should categorically denounce the recruitment and use of child soldiers," said Zama Coursen-Neff, children's rights director at Human Rights Watch.
"Commanders in affiliated armed groups should know that the recruitment and use of children under age 15 constitute war crimes."
The HPG signed an agreement in October 2013, stating that they would stop recruiting fighters under the age of 18.
"We will make all efforts to ensure that all 16-18 year olds are separated and kept away from combat zones," said Delal Amed, a HPG commander and signatory to the agreement.
HRW's report is not the first time that concerns have been raised over Kurdish militias recruiting boys and girls as young as eight.
A 2010 investigation by Denmark's Berlingske Tidende found the PKK had enlisted around 3,000 child soldiers, which UNICEF described at the time as "a clear violation of the children's convention".
Since that report, there have a number of subsequent reports that confirmed the PKK were flouting their agreement on banning child soldiers.
Kurdish militias are not the only groups recruiting children. HRW recently published a report on underage militants used by Sunni militias in Iraq, including Hashd al-Ashaari.
HRW's latest report on the issue was published in June 2015, which found that soldiers under the age of 18 were dying in battle.
"The YPG promised to stop sending children to war and it should carry out its promise," Fred Abrahams, special adviser at HRW, said in 2015.
HRW have called on PKK commanders to investigate the allegations and punish those responsible for abducting and recruiting children.
It has also called on the Iraqi government in Baghdad to act, as they are currently paying YBS forces and other Kurdish groups to fight against IS.