Shopkeepers in Manbij, a city in northwestern Syria under the control of the PKK's Syrian affiliate group, staged a strike on Sunday to protest the forced recruitment of dozens of youngsters by the terror group since early May.

Local sources on the ground, requesting anonymity due to security concerns, told Anadolu Agency (AA) that a complete shutdown was observed and businesses remained closed in protest to the People's Protection Units (YPG) terrorists.

In April, the YPG announced that those aged 18-30 should join the group before May 5, warning them of torture and brutality if they do not surrender. After the deadline was over, the terror group began to recruit the youngsters forcefully.

The terror group captured Manbij, west of the Euphrates River, in August 2016 with support of the U.S. military, which also has troops in the region.

The use of child soldiers, as well as other human rights abuses, by the YPG and the PKK have long been documented by the international rights groups, such as Human Rights Watch, Amnesty International and the United Nations.

In early March, digital evidence obtained by Turkish security forces had also revealed the recruitment of child soldiers by the YPG in Syria.

Digital evidence found on cameras and memory cards recovered from killed YPG terrorists and their bunkers during Turkey's Operation Olive Branch, launched on Jan. 20 to eliminate the YPG from northwestern Syria's Afrin province, showed children around 13 to 17 years old being recruited by the group.