(Reuters) - Kurdish forces backed by U.S.-led air strikes have regained control of at least 163 villages around the Syrian town of Kobani after driving back Islamic State militants in the past three weeks, a group monitoring the conflict said on Saturday.

The Britain-based Syrian Observatory for Human Rights said that although the Kurds had recaptured many villages since winning back Kobani in late January, their progress had been slowed by renewed clashes to the west and southwest of the town, where Islamic State had redirected its fighters.

The battle for the predominantly Kurdish town, known as Ayn al-Arab in Arabic, became a focal point for the U.S.-led air campaign against the al Qaeda offshoot in Syria.

Islamic State controls large areas of northern and eastern Syria, including a strip of territory across the northern Aleppo countryside and a corridor stretching southeast from Raqqa province to the frontier with Iraq.

The Syrian Kurds, who also received military support from Iraqi Kurdish peshmerga forces, said they drove Islamic State from the town near the Turkish border on Jan 26. U.S.-led forces have carried out almost daily air strikes on Islamic State targets around the area since late last year.

The Kurds were joined by several hundred rebel fighters in the battles for areas surrounding the town, the Observatory's founder Rami Abdulrahman said. The rebel groups included the Shams al-Shamal brigade and the Raqqa Revolutionaries Brigade, anti-Islamic State fighters from northern Syria who had battled alongside the Kurds to win back territory.

Islamic State's advance on Kobani last year with heavy weapons drove tens of thousands of residents over the border into Turkey. The Kurds, armed with mainly light weapons, called for international help and the town now lies in ruins.

(Reporting by Sylvia Westall. Editing by Jane Merriman)