Syrian Kurdish fighters advanced towards the town of Tal Abyad on the Turkish border on Thursday, backed by US-led coalition air strikes, a monitor said. Tal Abyad is under ISIS' control.
The Syrian Observatory for Human Rights (SOHR) said Kurdish People’s Protection Units (YPG) forces backed by Syrian opposition fighters "stormed the town of Suluk and took control of the eastern part of it."
Suluk is fully under ISIS control in Raqqa, northern Syria, lies to the east of Tal Abyad, a key border town that is controlled by the insurgent group.
Kurdish fighters are aiming to capture Tal Abyad in order to free up the route between Kobane to the west and Qamishli, further east along the Turkish border.With YPG’s advance into Suluk, the Kurdish forces are now 20 kilometres east of Tal Abyad.
Fierce clashes between ISIS and the YPG forces took place throughout on Thursday, according to the SOHR.
"The Kurds plan to lay siege to Tal Abyad," Observatory director Rami Abdel Rahman said.
The YPG has been backed by US-led air strikes targeting ISIS positions in the area, he added.
According to the SOHR, over 400 foreign fighters travelled to Syria to join the YPG in May only, in order to fight ISIS in Hasakah, Raqqa and Aleppo.
Foreign YPG fighters include Europeans, Australians, North and South Americans, in addition to thousands of Kurdish fighters who come from Turkey and Iran.
The latest fighting in the area has prompted a wave of refugees flee into neighbouring Turkey, which is already hosting 1.8 million Syrians.
Nearly 9,000 Syrian refugees have entered Turkey since last week, a Turkish official said on Wednesday.