TOPSHOT - Displaced Iraqi Christians take part in celebrations on October 18, 2016 in Arbil, the capital of the autonomous Kurdish region of northern Iraq, to mark the liberation of Qaraqosh, that was Iraq's largest Christian town before it was overrun by the Islamic State (IS) jihadi group in August 2014.
Tens of thousands of Iraqi forces were making gains from the Islamic State group in Mosul Tuesday in an offensive US President Barack Obama warned would be a 'difficult fight'.

 / AFP / SAFIN HAMED        (Photo credit should read SAFIN HAMED/AFP/Getty Images)