Kurdish-led forces in Syria have claimed control of the old city of Raqqa, the de facto capital of the self-declared Islamic State caliphate. The Syrian Democratic Forces (SDF), an alliance of Kurdish and Arab militias, have been battling to capture the city since June. US-led coalition air strikes and special operations forces are supporting them. <br/><br/>The SDF says, it has finally seized the remaining districts in the walled old city. The group says, its troops are now advancing into the west of Raqqa. The Islamic State terrorist group has been using the city's western districts to house its military and administrative facilities. But the IS terrorists there are now encircled without supplies. They have taken more than 20,000 citizens as hostages and human shields. <br/><br/>The office of the UN High Commissioner of Human Rights says US-led air strikes on Raqqa have caused heavy civilian casualties. It urges the coalition to quickly secure evacuation routes for residents