The Syrian Kurdish YPG militia said it began an advance toward an Islamic State-held town at the Turkish border on Saturday, thrusting deeper into the jihadists' stronghold of Raqqa province with the backing of US-led air strikes.
Redur Xelil, the YPG spokesman, told Reuters the YPG and smaller Syrian Arab rebel groups fighting alongside it had begun the move toward Tel Abyad after encircling the Islamic State-held town of Suluk 20 km (12 miles) to the southeast.
The advance raises the prospect of a big battle at the Turkish border between the well-organized YPG militia and Islamic State. Tel Abyad is important to Islamic State as the nearest border town to its de facto capital of Raqqa city.
Turkey says thousands of people have already fled across its border to escape fighting between the YPG and Islamic State near Tel Abyad.
The YPG has made a determined push into Raqqa province from neighboring Hasaka where, with the help of the US-led alliance, it has driven Islamic State from wide areas of territory since early May.
"The move toward Tel Abyad from the east began today after the completion of the Suluk blockade," Xelil said. "Many of the Daesh militants have fled (Suluk), apart from a group of suicide attackers inside the town and the booby traps, so we are very cautious about entering the town center," he added via Skype.
Daesh is an Arabic name for Islamic State.
The Syrian Observatory for Human Rights, a UK-based organization that tracks the war, said the YPG fighters were now half-way between Suluk and Tel Abyad.
With the help of US-led air strikes, the YPG fended off an Islamic State attack on the border town of Kobani, or Ayn al-Arab, in January. Since then, the YPG has emerged as the most significant partner on the ground in Syria for the US-led alliance that is trying to roll back Islamic State.
Washington has ruled out the idea of partnering with President Bashar al-Assad, who last month lost the city of Palmyra in central Syria to Islamic State — the first time the jihadists seized a city directly from government control.
For the YPG, dislodging Islamic State from Tel Abyad would help them to link up Kurdish-controlled areas of Syria in Hasaka province and Kobani.
The expansion of Kurdish influence in Syria near the border with Turkey is a concern for Ankara, which has long been worried about separatism among its own Kurdish population.
Turkish President Tayyip Erdogan on Thursday accused the West of bombing Arabs and Turkmens in Syria while supporting Kurdish "terrorist" groups he said were filling the void left behind.
Xelil said: "The help of the alliance forces has been very effective and accurate in its target selection."
The YPG is affiliated to the outlawed Kurdistan Workers Party (PKK) which has fought a decades-long insurgency against the Turkish state. The PKK is considered a terrorist group by Ankara, the United States and European Union.
