Turkey has been warned by a top UN official against killing civilians during its military offensive in north-eastern Syria.
The remarks late on Tuesday came less than 24 hours after footage emerged of what appeared to be summary executions by Turkish-aligned militiamen.
Adama Dieng, UN Secretary General Antonio Guterres's special adviser on genocide, and Karen Smith, special adviser on the responsibility to protect, said in a statement that civilians had been indiscriminately harmed.
“The Office of the High Commissioner for Human Rights has reported on several civilian casualties, including allegations of summary executions, and humanitarian actors report that at least 160,000 civilians have been displaced in the six days since the start of the military operation,” they said.
“The special advisers stressed that Turkish authorities and all parties to the conflict in Syria need to ensure strict adherence to the legal obligation to protect civilians.
''This is the responsibility of all state and non-state actors. No civilian should be forced to leave their home against their will.”
Their remarks came shortly before Turkish President Recep Tayyip Erdogan defied US calls for a ceasefire.
"They tell us 'to declare a ceasefire'. We can never declare a ceasefire," Mr Erdogan said, according to Turkey's Hurriyet daily.
UN officials earlier said pro-Turkish fighters last weekend might have committed war crimes for which Ankara could be held responsible.
Nine civilians were killed, said the Kurdish-dominated Syrian Democratic Forces, who Mr Erdogan's offensive is seeking to defeat.
Among them was Hevrin Khalaf, 35, secretary general of the Future Syria Party, who the SDF said was taken out of her car and killed.
The UN rights office in Geneva said its staff had seen two videos “showing what appear to be summary executions carried out by fighters belonging to the Ahrar Al Sharqiya armed group, which is affiliated with Turkey, on October 12".
The UN Security Council will discuss Turkey's week-long military assault on Wednesday.