A poster bearing a portrait of Syrian President Bashar al-Assad (R) and Russian President Vladimir Putin is seen ahead of a music concert in the ancient theatre of Syria's ravaged Palmyra on May 6, 2016.

Syrian troops backed by Russian air strikes and special forces on the ground recaptured UNESCO world heritage site Palmyra from Islamic State (IS) group fighters in March 2016.
 / AFP / LOUAI BESHARA        (Photo credit should read LOUAI BESHARA/AFP/Getty Images)