As they were driven out of Qayyara, ISIL fighters set more than a dozen oil wells on fire causing hundreds of injuries.

Qayyarah, Iraq – Ayad leans against the black wall of a partially destroyed home, gripping an AK-47 in his hands.

He takes a deep breath and sprints across the road, between puddles of spilled oil, towards another house that he imagines is full of fighters. Ayad is followed by five fellow soldiers. Ahead of them, tongues of fire lick upwards from burning oil wells. The scene is apocalyptic.

Suddenly, a worker shouts towards Ayad and his group: “Get away from there, kids – it’s dangerous.”

Ayad is seven years old; his Kalashnikov is made out of cardboard, and every day he plays with a group of two dozen other children around the fiery oil wells of Qayyara, Iraq.

The firefighters and engineers working to extinguish the flames repeatedly warn the children to stop wandering around the fields, but they do not listen. With no school to go to, this area has become their favourite playground.

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The children’s clothes, faces and hands are covered in soot. They occasionally cough from the fumes. Some of the older children wear worn-out cotton masks in an effort to protect their lungs.

On some days, the black smoke is so thick that it appears to be pitch dark at midday.

The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) invaded Qayyara in June 2014. The predominantly Sunni town, located about 60km south of Mosul, is rich in oil, with more than 60 wells. Most of its 20,000 residents remained in Qayyara after the ISIL invasion, living under the group’s rule for two years.

But on August 25, Iraqi forces pushed into the town, and ISIL quickly retreated. Before fleeing, ISIL fighters blew up an oil well in the middle of a residential area, destroying 20 homes. Oil still boils amongst the debris. In total, ISIL fighters set 15 oil wells in this area on fire as they retreated.

“They [ISIL] set the wells on fire because they wanted to black the sky and prevent air strikes, but they also did it as a means of retaliation against the local population,” says Bashir Murat, who is in charge of the Nineveh oil fields. The lack of electricity has made his job more difficult, as he needs power to pump water and extinguish the flames.

With no school to go to, this area has become the children’s favourite playground [Benedetta Argentieri/Al Jazeera]

“Once we start, it will take between 10 days to a month to stop it,” he says.

So far, Murat’s team has doused six of the 15 wells. Security is a primary concern, as ISIL might have placed explosive devices around the wells. “We have to be very careful when approaching,” Murat says.

This technique is not new: Saddam Hussein’s army torched hundreds of oil wells when retreating from Kuwait in 1991. It took nearly a year to completely extinguish the flames.

Meanwhile, the fumes are badly affecting local residents. The plumes of smoke are visible from kilometres away, with polluted air reaching the nearby towns of Haji Ali and Osaja, just across the Tigris. Further aggravating the situation, ISIL set alight a sulphur plant north of Qayyara on October 20. The toxic gas killed at least two people, and nearly 1,000 people had to be treated.

According to the Women and Health Alliance International, which has established field hospitals in the area, they are treating hundreds of people each day.

“We are worried about the situation,” mission leader Lana Simpraga tells Al Jazeera. Many children are suffering from bronchitis, or have developed rashes on their hands, feet or faces. Doctors and nurses are giving cortisone to the most serious cases, but due to a shortage of medicines, not everyone can be treated.

On some days, the black smoke is so thick that it appears to be pitch dark at midday [Benedetta Argentieri/Al Jazeera]

There are also shortages of food and water. The British NGO Oxfam is currently working on a project to restore the water plants in nearby villages, which were hit during the recent battle.

“I meet families every day who tell me their children are very sick because of the air pollution and lack of access to clean drinking water. The teams are delivering chlorine to two water treatment plants in the area and fuel to ensure the plants are able to continue working,” Amy Christian, an Iraq spokeswoman for Oxfam, tells Al Jazeera.

Access to the area remains very difficult, with ISIL carrying out daily attacks. Supply lines have been cut, with frontlines nearby to the north and south.

With the crisis still going on, the Iraqi army has tried to convince residents in the immediate area of the burning wells to relocate, but many refused, saying they would rather stay at home than go to a crowded camp.

One of Ayad’s favourite spots to hide while he plays war games with his friends is under a house collapsed by an air strike. A dead body lies under the debris.

“It’s ISIL,” he says, smiling.