ISIS captured a town from the Kurdish People’s Protection Units (YPG) north of Raqqa city on Monday, the Syrian Observatory for Human Rights (SOHR) has reported.
ISIS lost the town of Ain Issa to YPG, backed by US-led air strikes two weeks ago.
The YPG now controls the border with Turkey from Syria’s northeast to east of the town of Jarabulus after the group captured north Syrian city of Tal Abyad last month.
Tal Abyad was a major artery through which foreign fighters travelled to Syrian territory controlled by ISIS. It is an oil-rich city located 65 kilometres east of Kobane and also a key city between Turkey and the northern Syrian province of Raqqa.
The YPG is the military wing of Kurdish Democratic Union Party (PYD). The PYD is seen as a Syrian affiliate of the outlawed PKK.
The YPG has emerged as the main partner for the US-led alliance fighting ISIS on the ground in Syria. Backed by Iraqi Kurdish Peshmerga fighters and air strikes, the YPG defeated ISIS in the border town of Kobane in January.
The PYD is also the only Syrian Kurdish party that is not under the umbrella of the Kurdish National Coalition, or Kurdnas, formed through the efforts of Kurdish Regional Government President Massoud Barzani.
Turkey hosts an estimated 1.8 million Syrian refugees, including around 200,000 from Kobane, more than any of Syria’s other neighbours and one of the biggest refugee populations in a single country anywhere in the world.
According to UN estimates, more than 220,000 people have been killed in Syria since the start of the ongoing civil war, which started as an uprising against the country’s repressive government and descended later into a complex multifaceted conflict. More than 6.7 million people have fled the country while millions of others are displaced internally.