The United Nations human rights council is gathering information about a video that appears to show the summary executions of Kurdish prisoners by the Turkish military.
News of the investigation came as UN Secretary-General Antonio Guterres called for a de-escalation of the Syrian conflict.
The Syrian army has deployed to the northeast after sealing a deal with the Kurdish-led Syrian Democratic Forces (SDF).
Syria says the deployment will support the SDF in countering Turkish aggression.
Al Jazeera's Charles Stratford reports live from Akcakale, Turkey.
Al Jazeera talks to Mehmet Celik, the managing editor of Daily Sabah.
