In a series of statements since Sunday, President Recep Tayyip Erdogan has threatened to launch an operation against towns in Syria controlled by the Kurdish People's Protection Units (YPG), calling the areas "nests" of terror.

The YPG has taken advantage of years of war to carve out a de facto autonomous region in Syria's north and northeast, notably the region of Afrin.

Several thousand people demonstrated against Erdogan on Thursday, January 18, in Jawadiyeh, in the northeastern province of Hasakeh, AFP reported.

Protestors shouted "Down, down, Erdogan!" and "With our soul, with our blood, we are with you Afrin!"

Signs in Arabic and Kurdish read: "We condemn attack by the Turkish state against our people in Afrin."

Several other parts of Kurdish-controlled territories saw similar gatherings, notably Afrin itself, where organizers said tens of thousands of people took to the streets despite the rain.

On Sunday, the U.S.-led coalition fighting Islamic State (ISIS) in Syria announced that it was training local fighters, including Kurdish fighters, as a "border security force".

Damascus said Thursday that Syria's air force could destroy any Turkish warplanes used over its territory.

Reporter’s code: 50101