Raqqa’s underground caliphate
In October of last year the rebel Syrian Democratic Forces with support of the US led coalition entered Raqqa, the former capital of the Islamic State armed group.
Civilians returning home not only found their property marked and vandalised but also underground tunnels.
The vast underground complex was not only built to provide cover from coalition aerial bombardment; it housed bunkers, storage facilities and escape routes for Islamic State fighters.
In this fourth part in a series of 5, Filip Warwick reports from Raqqa.