Syrian Democratic Forces have breached a strategic wall surrounding the Old City of Raqqa in ISIS’s self-declared capital on Monday.
The SDF, supported by US-led coalition air strikes, has spent months encircling the city.
The operation was “a key milestone” in the campaign to “liberate the city,” Brett McGurk, the US envoy for the anti-ISIS coalition, said on his official Twitter account.
IS seized Raqqa in 2014, proclaiming it the capital of a “caliphate”.
The city has been an important hub for the jihadist group’s operations, though as the SDF closed in, key IS officials are believed to have fled from there towards Deir al-Zour province, which is mostly under IS control.
The US-backed forces have been gradually advancing on the city since November, and launched an offensive to take it on 6 June.
The battle for Raqqa is not dissimilar to that of Mosul, where US-backed Iraqi forces are fighting to expel the last of ISIS fighters from Iraq’s second-largest city. But the fight to retake Raqqa has gone quicker, with attacking forces gradually forcing a diminishing number of ISIS fighters into a smaller area of narrow streets around the ancient mosque of Rafiqa, which has already been extensively damaged.
The coalition hopes that the loss of Raqqa and Mosul will demoralize ISIS confidence.