Syrian rebels backed by Turkish tanks and warplanes have begun an offensive to take "Islamic State"-held Dabiq, a town that has ideological significance for the extremist group.

The Turkish-backed rebels have for more than a week cleared surrounding villages and are now 2.5 kilometers (1.5 miles) from Dabiq, the UK-based Syrian Observatory for Human Rights said on Saturday.

The monitoring group said IS had stationed 1,200 fighters to defend the town, which is surrounded from three sides.

Turkish President Recep Tayyip Erdogan on Saturday confirmed the rebels' next target was Dabiq, where according to IS ideology, an apocalyptic battle will take place between Muslims and infidels.

However, IS in a recent article on its al-Naba online publication appeared to backtrack on the significance of Dabiq, saying that the current battle was not the one envisioned in the prophecy. Dabiq is also the name of the terror group's English-language propaganda magazine.

Turkey intervened in northern Syria on August 24 to clear IS from a section of the border and block the US-backed Syrian Kurdish YPG militia from advancing further west.

Dubbed "Operation Euphrates Shield," the military operation involves Turkish tanks, soldiers and artillery backed by US-led coalition airstrikes and ground forces from Turkey-backed rebels.

The intervention has succeeded in wresting control of the border towns of Jarabulus and Al-Rai from IS, dealing a major blow to the group in the northern Aleppo countryside.

Turkey has in effect created a limited buffer zone along the border, and on Saturday Erdogan said the goal was to create a safe zone of 5,000 square kilometers in northern Syria.

"Operation Euphrates Shield" comes after IS suffered repeated setbacks over the past year at the hands of the US-backed Syrian Defense Forces (SDF), a group that is dominated by the Syrian Kurdish YPG militia but also includes Arab, Turkmen and Christian fighters.

The SDF's advances have caused friction between Turkey and its NATO ally the United States, which considers the Syrian Kurds some of the best fighters against IS. The US has had to step in to focus Ankara's energies on IS, while encouraging the Syrian Kurds to back away from moving further west in order to avoid clashes with Turkey.

The YPG is close to the Kurdistan Workers' Party (PKK), which has fought a three-decade-long war for greater rights for Turkey's Kurdish minority. Turkey is concerned that the Syrian Kurdish gains and drive for autonomy in Syria will have a knock-on effect on its own Kurdish population and lead to the dissolution of Syria.

The offensive on Dabiq comes at a time when IS is under pressure on all fronts as the Iraqi army prepares for an offensive to retake Mosul, Iraq's second-largest city, which fell to the Sunni extremist group in the summer of 2014.

cw/rc (AFP, dpa, Reuters)