Kurdish forces held out in a key border town Tuesday seven days into a deadly Turkish invasion of northeastern Syria that has caused mass displacement and reshaped the political map.

Using a dense network of tunnels, berms and trenches, Kurdish fighters from the Syrian Democratic Forces (SDF) have been mounting a desperate defense of Ras al-Ain.

They launched “a large counterattack against Turkish forces and their Syrian proxies near Ras al-Ain,” the Britain-based Syrian Observatory for Human Rights said.

They launched “a large counterattack against Turkish forces and their Syrian proxies near Ras al-Ain,” the Britain-based Syrian Observatory for Human Rights said.