Iraqi army vehicles are seen during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





Iraqi forces gather during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





Iraqi security forces military a vehicle is seen during an operation to attack Islamic State militants in Mosul, Iraq, October 21, 2016. (Photo by Reuters/Stringer)





People inspect the damage after an attack by Islamic State militants in the city of Kirkuk, Iraq, October 22, 2016. (Photo by Ako Rasheed/Reuters)





People inspect the damage after an attack by Islamic State militants in the city of Kirkuk, Iraq, October 22, 2016. (Photo by Ako Rasheed/Reuters)





Iraqi forces wear protective masks after winds brought fumes from a nearby sulfur plant set alight by Islamic State militants, at south of Mosul in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





An Iraqi army vehicle is seen during an operation to attack Islamic State militants in Mosul, in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Civilians return to their village after it was liberated from Islamic State militants, south of Mosul in Qayyara, Iraq, October 22, 2016. The fumes in the background are from oil wells that were set ablaze by Islamic State militants. (Photo by Alaa Al-Marjani/Reuters)





A man returns to his village after it was liberated from Islamic State militants, south of Mosul in Qayyara, Iraq, October 22, 2016. The fumes in the background are from oil wells that were set ablaze by Islamic State militants. (Photo by Alaa Al-Marjani/Reuters)





A Christian Iraqi special forces soldier walks in a church in Bartella, east of Mosul, Iraq October 22, 2016. (Photo by Goran Tomasevic/Reuters)





A man returns to his village after it was liberated from Islamic State militants, south of Mosul in Qayyara, Iraq, October 22, 2016. The fumes in the background are from oil wells that were set ablaze by Islamic State militants. (Photo by Alaa Al-Marjani/Reuters)





Iraqi army guard a checkpoint in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi army guard a checkpoint in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





A woman returns to her village after it was liberated from Islamic State militants, south of Mosul in Qayyara, Iraq, October 22, 2016. The fumes in the background are from oil wells that were set ablaze by Islamic State militants. (Photo by Alaa Al-Marjani/Reuters)





Fire trucks are seen in Qayyara, Iraq, October 22, 2016. The fumes in the background are from oil wells that were set ablaze by Islamic State militants. (Photo by Alaa Al-Marjani/Reuters)





An Iraqi army vehicle is seen during an operation to attack Islamic State militants in Mosul, in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi army guard a checkpoint in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





A soldier guards a checkpoint in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi pro-government forces are seen in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi pro-government forces are seen in Qayyara, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi army are seen in Qayyara, Iraq, October 22, 2016. The fumes in the background are from oil wells that were set ablaze by Islamic State militants. (Photo by Alaa Al-Marjani/Reuters)





Iraqi army are seen in Qayyara, Iraq, October 22, 2016. The fumes in the background are from oil wells that were set ablaze by Islamic State militants. (Photo by Alaa Al-Marjani/Reuters)





Iraqi Kurdish security forces patrol a street in the city of Kirkuk, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi Kurdish security forces patrol a street in the city of Kirkuk, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi Kurdish security forces patrol a street in the city of Kirkuk, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)





Iraqi Kurdish security forces gather in the city of Kirkuk, Iraq, October 22, 2016. (Photo by Alaa Al-Marjani/Reuters)