Turkey is preparing to launch a long-threatened military operation in northeast Syria to remove Kurdish-led forces from the border area and create a "safe zone" to resettle millions of Syrian refugees.
The move came after the United States announced it was withdrawing its troops from the region, effectively abandoning the Syrian Democratic Forces (SDF), its main ally in the battle against the Daesh armed group.
The SDF, led by the Kurdish People's Protection Units (YPG), has denounced Washington's move as a "stab in the back". Turkey considers the YPG a "terrorist" group.
The United Nations, the European Union and other world powers have expressed alarm over the Turkish plan, warning that any military action could exacerbate the suffering of Syrians already beleaguered by eight years of conflict.
The head of the Arab League says he is alarmed at Turkey's planned military offensive into northeastern Syria, against the Syrian Kurdish fighters there.
In a statement on Wednesday, Ahmed Aboul Gheit said that such an invasion would be a "blatant violation of Syria's sovereignty and threatens Syria's integrity."