TOPSHOT - Turkish-backed Syrian fighters burn a flag at the entrance of a tunnel, said to have been built by Kurdish fighters, in the Syrian border town of Tal Abyad, on October 21, 2019. - The Kurdish-led Syrian Democratic Forces fully withdrew from a Turkish-encircled town in northern Syria on Sunday, in what appeared to be the start of a wider pullout under a ceasefire deal. The Kurds have agreed to withdraw from an Arab-majority stretch of border from Tal Abyad to Ras al-Ain, around 120 kilometres (70 miles). (Photo by Bakr ALKASEM / AFP) (Photo by BAKR ALKASEM/AFP via Getty Images)