KURDISH guerillas launched their long-awaited offensive on the Isis stronghold of Raqqa yesterday — advancing from three sides on the Syrian town.

The US-backed Syrian Democratic Forces (SDF) — dominated by the Kurdish separatist YPG militia — attacked from the west, north-east and east of the city on the north bank of the Euphrates.

Unconfirmed reports said they had entered the city’s outskirts.

SDF spokesman Talal Silo said: “The start of the great war which aims to liberate Raqqa city, and we declare that our forces are ready for the fight with high morale and great preparations.

He said the operation had been discussed beforehand with “our partners on the ground, the international coalition.”

The US-led coalition also issued a statement, stressing the role of the “Syrian Arab Coalition” within the SDF.

“The multi-ethnic SDF is the coalition’s local ground force partner in the fight against Isis in northern Syria,” it said.

Coalition commander General Steve Townsend said the impending loss of the extremists’ “twin capitals” of Raqqa and Mosul in Iraq would make it “hard to convince new recruits that Isis is a winning cause.”

But there are signs Isis has withdrawn all but a rearguard force across the river to the unguarded south.

Last week the Russian Defence Ministry released video of its aircraft blitzing fleeing Isis convoys south of Raqqa.

And the death cult’s last-ditch bid to capture the besieged city of Deir Ezzor to the south-east intensified yesterday.

The Syrian armed forces said Isis continued the assaults on the southern edge of the city.

Meanwhile the Syrian army continued its offensive against Isis south-east of Aleppo, advancing into the west of Raqqa province south of the Euphrates and taking back a string of villages.

Earlier Syria’s Sana news agency reported that coalition air strikes had killed 12 civilians in Raqqa.

Turkish Prime Minister Binali Yildirim said yesterday his country would respond if an offensive by the SDF on Raqqa poses a threat to Turkey.

He criticised the United States for launching the Raqqa offensive with SDF.