A Russian Defence Ministry source says, Kurdish forces have allowed ISIS an open corridor to flee the besieged city of Raqqa in Syria. Russian special forces have apparently started an operation to prevent the terrorists leaving the area. RT's Roman Kosarev has more on this. br br RT LIVE br Subscribe to RT! br Like us on Facebook Follow us on Twitter Follow us on Instagram Follow us on Google+ Listen to us on Soundcloud: br RT (Russia Today) is a global news network broadcasting from Moscow and Washington studios. RT is the first news channel to break the 1 billion YouTube views benchmark.