Oilfields burned by Islamic State fighters are seen in Qayyara, south of Mosul, Iraq December 21, 2016. (Photo by Ammar Awad/Reuters)





An oil worker uses a hose in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq December 21, 2016. (Photo by Ammar Awad/Reuters)





Men stand in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq December 21, 2016. (Photo by Ammar Awad/Reuters)





Oil workers react in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq December 21, 2016. (Photo by Ammar Awad/Reuters)





Oil workers react in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq December 21, 2016. (Photo by Ammar Awad/Reuters)





A policeman stands in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq December 21, 2016. (Photo by Ammar Awad/Reuters)





Oil workers react in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq December,21, 2016. (Photo by Ammar Awad/Reuters)





Oilfields burned by Islamic State fighters are seen in Qayyara, south of Mosul, Iraq December,21, 2016. (Photo by Ammar Awad/Reuters)





Men stand in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul,Iraq.December,21, 2016. (Photo by Ammar Awad/Reuters)





Men stand in front of oilfields burned by Islamic State fighters in Qayyara, south of Mosul, Iraq, December 21, 2016. (Photo by Ammar Awad/Reuters)





A displaced woman who was rescued after being kidnapped by Islamic State militants, poses at Khazer camp, Iraq, December 20, 2016. (Photo by Ammar Awad/Reuters)





A displaced Iraqi woman, who fled the Islamic State stronghold of Mosul, receives aid in the east of Mosul, Iraq, December 21, 2016. (Photo by Khalid al Mousily/Reuters)





Displaced Iraqis from Mosul, who are fleeing from Islamic State militants, gather to receive aid in the east of Mosul, Iraq, December 21, 2016. (Photo by Khalid al Mousily/Reuters)





Displaced Iraqis from Mosul, who are fleeing from Islamic State militants, receive aid in the east of Mosul, Iraq, December 21, 2016. (Photo by Khalid al Mousily/Reuters)





Iraqi rapid response forces cook food in their headquarters during the war against the Islamic state militants east of Mosul, Iraq, December 21, 2016. (Photo by Khalid al Mousily/Reuters)





Iraqi rapid response forces eat food in their headquarters during the war against the Islamic state militants east of Mosul, Iraq, December 21, 2016. (Photo by Khalid al Mousily/Reuters)





A member of Iraqi rapid response forces coock food during fighting against the Islamic state militants east of Mosul, Iraq, December 21, 2016. (Photo by Khalid al Mousily/Reuters)





A man wounded in a bomb attack receives treatment at a hospital in the northern Iraqi city of Erbil, December 22, 2016. (Photo by Ammar Awad/Reuters)





A man wounded in a bomb attack in Kokjali, receives treatment at a hospital in the northern Iraqi city of Erbil, December 22, 2016. (Photo by Ammar Awad/Reuters)





men wounded in a bomb attack in Kokjali, receive treatment at a hospital in the northern Iraqi city of Erbil, December 22, 2016. (Photo by Ammar Awad/Reuters)





A man wounded in a bomb attack in Kokjali, receives treatment at a hospital in the northern Iraqi city of Erbil, December 22, 2016. (Photo by Ammar Awad/Reuters)





Iraqi rapid response forces ride in a military vehicle during a fight with Islamic State militants in Intisar district of eastern Mosul, Iraq, December 22, 2016. (Photo by Khalid al Mousily/Reuters)





A woman walks across the street during a fight with Islamic State militants in Intisar district of eastern Mosul, Iraq, December 22, 2016. (Photo by Khalid al Mousily/Reuters)





Iraqi rapid response forces gather during a fight with Islamic State militants in Intisar district of eastern Mosul, Iraq, December 22, 2016. (Photo by Khalid al Mousily/Reuters)





A member of Iraqi rapid response forces take his position during a fight with Islamic State militants in Intisar district of eastern Mosul, Iraq, December 22, 2016. (Photo by Khalid al Mousily/Reuters)





Iraqi rapid response forces ride in a military vehicle during a fight with Islamic State militants in Intisar district of eastern Mosul, Iraq, December 22, 2016. (Photo by Khalid al Mousily/Reuters)





U.S. army forces participate in combat training in the northern Iraqi city of Erbil, December 22, 2016. (Photo by Ammar Awad/Reuters)





A member of the U.S. army forces participates in combat training in the northern Iraqi city of Erbil, December 22, 2016. (Photo by Ammar Awad/Reuters)





Iraqi priest walks past a market for Christmas decorations in the northern Iraqi city of Erbil, December 23, 2016. (Photo by Ammar Awad/Reuters)





A shop owner for Christmas decorations waits for customers at a market in the northern Iraqi city of Erbil, December 23, 2016. (Photo by Ammar Awad/Reuters)





Iraqi people shop for Christmas decorations at a market in the northern Iraqi city of Erbil, December 23, 2016. (Photo by Ammar Awad/Reuters)





Iraqi people shop for Christmas decorations at a market in the northern Iraqi city of Erbil, December 23, 2016. (Photo by Ammar Awad/Reuters)





Kayaks, 7, poses for a picture holding toy gun in a camp where Christians displaced by Islamic State militants are living, in Irbil, Iraq, Friday, December 23, 2016. Iraq’s Christians are marking the holiday in his camp for displaced people with a sense of worry and despair, unable to return to their towns they were forced to flee two years ago by the Islamic State group’s onslaught. (Photo by Manu Brabo/AP Photo)