Firefighting teams try to extinguish an oil fire November 27, 2016 as smoke billows from one of the remaining oil wells set ablaze by ISIL in their retreat from Qayyarah at the start of the Mosul offensive which began more than a month prior. (Photo by Byron Smith/ZUMA Wire/Rex Features/Shutterstock)

A girl holds her brother in her arm as black smoke rises after an oil well set on fire in the center of al-Kayyara town to the south of Daesh terror organization-held Mosul in Iraq on October 25, 2016. The oil well in the center of al-Kayyara town, which was set alight by retreating Daesh militants in advance of the Iraqi army's takeover of the town on August 24, 2016 has still not entirely been put out. The raw petrol which is still alight is creating black clouds above the city. The residents and wildlife beneath this polluting smoke cloud may find their health at risk. The effects of the fire in the town center on unprotected civilians' health can easily be seen on the hands and faces of children playing on the street. (Photo by dris Okuducu/Anadolu Agency/Getty Images)

Fighters from the Democratic Forces of Syria prepare their weapons in the southwestern countryside of Hasaka, Syria February 17, 2016. Picture taken February 17, 2016. (Photo by Rodi Said/Reuters)

Rebel fighters from the Jaish al- Fatah (or Army of Conquest) brigades manoeuver an alleged explosive- rigged make- shift armoured vehicle during a major assault on Syrian government forces West of Aleppo city on October 28, 2016 Syrian opposition fighters launched a major assault on government forces to break a months- long siege of rebel- held neighbourhoods of the battered city of Aleppo. Rebel groups including the powerful Ahrar al- Sham faction and former Al- Qaeda affiliate Fateh al- Sham Front fired waves of rockets into government- held western Aleppo, killing at least 15 civilians, a monitor said. (Photo by Omar Haj Kadour/AFP Photo)

A Iraqi soldier of the 9th division is seen within a Humvee in Shyma district in Mosul, Iraq, Tuesday, December 6, 2016. Iraqi forces, backed by the U.S.-led international coalition, launched a campaign in October to retake Mosul, the country's second largest city and IS's last major urban bastion in Iraq. (Photo by Manu Brabo/AP Photo)

Civilians present their rations cards in order to receive humanitarian food aid being distributed by the Iraqi Red Crescent, in the eastern side of Mosul, Iraq, Tuesday, January 31, 2017. Iraqi forces declared Mosul's eastern half fully liberated, just over three months after the operation to retake the city from IS was formally launched in October. (Photo by Khalid Mohammed/AP Photo)

A man carrying an axe walks past a house marked with bullet holes in Gyallesu district after recent clashes between Shi'ites and the army in Zaria, Kaduna state, Nigeria, February 3, 2016. Sectarian tensions are rising in Nigeria's Muslim north, where hundreds of Shi'ites were killed in clashes with the army in the town of Zaria in December, according to Shi'ites and rights groups. Following the clashes, bulldozers sent by the state levelled Shi'ite shrines, a cemetery and offices in the deeply divided town. The region is already grappling with an insurgency waged by the jihadist Boko Haram group. (Photo by Afolabi Sotunde/Reuters)

An Iraqi Army member launches a rocket during the operation to retake Mosul from Daesh terrorists in Jadid neighborhood as the clashes between Iraqi Army and Daesh terrorists continue in Mosul, Iraq on April 2, 2017. (Photo by Hemn Baban/Anadolu Agency/Getty Images)