At least two Kurdish prisoners were killed by Turkish-backed militants in Syria on Saturday, just days after President Trump’s announcement of a U.S. troop withdrawal sparked warnings that the move could trigger violence. According to a video of the killing, one of the prisoners was lying on the side of the road with his hands bound behind his back when he was shot at close range by two militants. The other prisoner, who was shown wearing a military uniform, was also later executed, according to a fighter cited by The New York Times. Just days after Trump’s announcement, the Turkish military began moving into northern Syria and menacing the Kurds, who were key American allies against ISIS.

By pulling U.S. troops out, Trump also left the Kurds to handle thousands of captured ISIS fighters on their own. The president’s decision has been criticized by Democrats in Congress, as well as some of his Republican allies. The Kurds have since appealed directly to Congress for help in stopping the invasion that could spark conflict across the Middle East.