SDF battles Turkish-backed forces to defend Ras al Ayn - AFP

Kurdish forces are battling to defend the key northeastern Syrian border town of Ras al Ayn from Turkish-backed forces on day seven of the Turkish offensive in the region, AFP reported. 

The Kurdish-led Syrian Democratic Forces (SDF) are mounting a desperate rearguard of the town using tunnels, berms and trenches, it said. 

Clashes around the town continue despite repeated claims by Turkey that it had captured the area, AFP reported.

Kurdish fighters have launched "a large counterattack against Turkish forces and their Syrian proxies near Ras al-Ain," according to Britain-based Syrian Observatory for Human Rights.

Turkey launched an offensive, dubbed Operation Peace Spring, on Oct.9, aiming to create a safe zone stretching 30 kilometres (20 miles) from the border into Syrian territory that is clear of the majority-Kurdish Syrian Democratic Forces (SDF).

Ankara sees the SDF, which has spearheaded the U.S.-led war on the Islamic State (ISIS) in the region, as an existential threat due to its links to the outlawed Kurdistan Workers’ Party (PKK), an armed group that has been at war in Turkey for Kurdish self-rule for three decades. 

Turkey aims to use the safe zone to settle up to 3 million of the 3.6 million Syrian refugees currently hosted by the country.

Turkish-backed forces have since Oct. 9 have secured more than 100 kilometres (60 miles) of border, however, Ras al Ayn, known as Siri Kani in Kurdish, has held out, AFP reported.

With U.S. forces withdrawing from the region, Syrian regime backer Russia has moved its troops into new areas, it said. 

Moscow has vowed to prevent clashes between the two sides.

At least 160 civilians have been killed, mostly Kurds, and some 160,000 people have been displaced since the beginning of the offensive, according to U.N. Office for the Coordination of Humanitarian Affairs.

Numerous aid groups, such as Doctors Without Borders and Mercy Corps, have pulled out international workers and halted work, however, UN agencies continue to operate.