The Kurdish fighters on Monday captured a key town in northern Syria from the Islamic State (IS) militants, a monitor group reported.

The town of Sarin in the countryside of the northern province of Aleppo province has been used by the IS militants as a launching pad for their attacks against the predominantly-Kurdish city of Ayn al-Arab, also known as Kobane, in the northern countryside of Aleppo, close to the Turkish borders, according to the Syrian Observatory for Human Rights.

The Britain-based watchdog group said Kurdish People's Protection Units (YPG) succeeded in capturing the town after 20 days of intensive battles against the IS.

With the capture of the town, the eastern bank of the Euphrates River has become clear of the IS militants all the way to the Turkish borders, said the Observatory, which relies on a network of activists on ground.

The U.S.-led anti-terror coalition has backed the Kurds in their recent push against the IS in Sarin, the Observatory added.

The Kurds have been making notable gains recently, stripping the IS of key areas in northern Syria along the borderline with Turkey.

In an earlier report, the Observatory said the IS presence on the Turkish borders is diminishing.

Last month, the YPG, backed by Syrian rebel groups and U.S.-led coalition, drove the IS out of the city of Tal Abyad on the borders with Turkey.