S. backed fighters, known as the Syrian Democratic Forces, say they're now combating Islamic State inside Rakka's old city, entering the district after breaching holes in an 8th Century Wall the U.S. Military says was booby trapped with land mines. Reuters Angus McDowell has been watching the story from Lebanon.
>> The attack on the city of Rakka itself 4 weeks ago came after months of fighting, to isolate the city from the North, East and West. To the South, it's bordered by the Euphrates and it was only a few days ago that the SDF finally managed to take the south bank of the Euphrates, completely cutting the city off.
All the way through it has faced the same sorts of problems. There's a bedeviled advances against the Islamic State in other cities. It faces fighters coming up from behind their lines, using tunnels dug before the attack was started. It's facing drone attacks to drop hand grenades onto fighters.
And of course, it's facing car bombs, the most lethal and one of the most favorite tactics that the jihadists use. Reaching the old city walls, starting to fight inside the old city is hugely important for the SDF. Not only does it mean that they are now fighting inside the very heart of Islamic State's Syrian capital, but it also means that they've penetrated what seemed to be one of its fiercest lines of defense.
Because around the old wall, there are only several gateways. By blowing holes through the old walls, the SDF fighters are able to advance. But of course that comes at the cost, yet more of Syria's priceless heritage.