Nine child soldiers were handed over on Friday to UN peacekeepers in the Mali city of Kidal, which is controlled by a former rebel group, a UN spokesman announced in New York.
"Good news from our colleagues in the peacekeeping mission in Mali.... Nine child combatants were handed over to the UN mission in Kidal this morning," the spokesman, Stephane Dujarric, told reporters.
"The mission is organizing their transportation to Gao and making arrangements for their care by child protection officials pending reunification with their family," he added, without giving the ages of the children.
Fighting between the ex-rebels of the Coordination of Movements of Azawad (CMA) and the pro-government Platform group has worsened in recent weeks in northern Mali, in repeated violation of a 2015 ceasefire.
"We were able to establish that the armed groups had minors in their ranks," Guillaume Ngefa, director of the human rights division of the UN mission to Mali, said in a statement Thursday.
"What is extremely concerning is that among the 33 people currently held prisoner by the CMA in Kidal, eight are children," he added, saying the children could be soldiers.
The conflict dates back to 2012, when key cities in northern Mali fell under the control of jihadist groups linked to Al-Qaeda, who exploited an ethnic Tuareg-led rebel uprising.
The armed groups accused of abuses by the UN operate in areas where Mali's army is absent or has a very limited presence.
Although the Islamists were largely ousted by a French-led military operation, attacks have continued on UN and French forces, civilians and the Malian army.
Allegations of collusion between the former rebels and jihadists continue to circulate.