Airstrikes and ground operations in northern Syria by Turkey against Kurdish forces have left civilians dead and forced tens of thousands to flee their homes, United Nations agencies said on Friday.

The agencies warn of a "humanitarian catastrophe" in the war-torn country if the military operation continues.

While expressing concern about the operation, the UN's emergency relief chief Mark Lowcock noted that the Turkish Government had "assured me that they attach maximum importance to the protection of civilians and the avoidance of harm to them."

"We have there all the ingredients for unfortunately yet another humanitarian crisis in Syria," Jens Laerke from the Office for the Coordination of Humanitarian Affairs (OCHA) said.

The Turkish offensive was launched on Wednesday after U.S. President Donald Trump announced that he would pull American forces from Syria's northern frontier, where they served as a buffer between the Turkish military and the Kurdish-led Syrian Democratic Forces.

As of Thursday evening, the UN human rights office, OHCHR, reported that seven civilians, including two women and a boy, had been killed in the first two days of the Turkish operation.

On his part, the U.N. Secretary-General on Thursday called for a de-escalation of the conflict in Syria, saying that he did not "believe in military solutions for the Syrian problem, also for any other problem in the world. I always strongly believe in political solutions."

(Information obtained from UN)