Humanitarian concerns are growing as people caught in the crosshairs of the Turkish incursion into northeastern Syria try to flee for safety, and groups are scrambling to aid them.

"There are big concerns about what is going on in northeastern Syria with the Turkish military aerial assaults and ground operations," Fr Emanuel Youkhana said by phone from northern Iraq, bordering the area.

Fr Youkhana, a priest, or archimandrite, of the Assyrian Church of the East, runs Christian Aid Program Northern Iraq (CAPNI), a Christian program for displaced Iraqis around the city of Dahuk. The UN refugee agency, UNHCR, has reported that so far 1,000 Syrians have fled over the border into northern Iraq.

"The numbers are increasing," Fr Youkhana said. "CAPNI staff are on the border of Fishkhabur, and they are set up now in the camps to assist those fleeing."

Fishkhabur is a town on the northwestern edge of Iraqi Kurdistan, principally inhabited by Chaldean Catholic Assyrians and some Kurds.

Karl Schembri, a spokesman for the Norwegian Refugee Council, said: "The situation for many of the people is utter chaos: fear gripping the entire area, not know what is going to happen next, where the next attacks will be. A lot of...displacement happening, the latest figures speak of around 200,000 people because of the fighting. There have been displacement camps that have closed down with people evacuated to other areas, which are hopefully safer."

About 50,000 Syrian refugees are expected to cross into northern Iraq over the next six months, according to the UNHCR. The migration is spurred by the Turkish military operation, which is using Syrian militants from Islamic State and al-Qaida as part of its ground troops fighting Kurdish and Syriac Christians of the Syrian Democratic Forces.

The Syrian Democratic Forces were, until recently, America's ally in fighting Islamic State in Syria and ending its territorial caliphate there. The forces lost about 11,000 fighters waging war against the terror group. The US troop pullback and Turkish offensive has raised fears of an Islamic State resurgence.