Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

KYIV, Ukraine – Wind-whipped wildfires have in recent days raged perilously close to the exclusion zone at Chernobyl, the site of what is considered to have been the world’s worst nuclear disaster.

But these fires were no accident — they were set by villagers who were clearing their land for planting, burning the grass away just as their forefathers had done.

They illustrate the tension that can exist between age-old traditions and modern imperatives. The question for authorities is this: how to reconcile the wish of farmers and others to continue a practice that may have been going on for generations with the need to contain radioactive waste for years to come?

The Chernobyl nuclear accident took place April 26, 1986, near Pripyat, in the north of the country, which was then part of the Soviet Union. A reactor core fire, sparked by an uncontrolled reaction during a routine test, released radioactive contamination into the air for 10 days. And that contamination rained down on parts of the Soviet Union and Western Europe.

A forest fire burns near Krasiatychi, Ukraine, last week. Oksana Parafeniuk / for NBC News

Structures now contain the radioactivity. But damage to those structures could again release contamination, environmentalists warn.

They say there is no place in the modern world for the burning of fields — especially near the site of the largest nuclear accident the world has known.

“Our society is on the verge of development when we can’t afford to preserve such extreme traditions anymore,” Sergiy Zibtsev, head of the Regional Eastern Europe Fire Monitoring Center, told NBC News.

For the moment, though, it is not nuclear contamination that is bothering the residents of Kyiv, 80 miles to the south. It is the smoke from the dozens of fires, some of which had spread by April 3 to the containment zone.

The only way people under coronavirus lockdown in Kyiv have been able to breathe fresh air has been to open the windows. But over the last 11 days, the air has tasted bitter and dried the nostrils. And in the distance, residents can see the smoke rising into the sky.

It wasn’t until Tuesday that residents breathed fresh air, as the rains poured down and some 400 firefighters tackled the fires.

A tractor operator makes a trench in the forest to prevent fire from spreading in the forest near Krasiatychi, Ukraine last week. Oksana Parafeniuk / for NBC News

Emergency workers managed several days ago to contain the initial bout of fires that tore through forests around the site of the 1986 nuclear disaster. Ukrainian authorities have played down any radiation risk.

The state emergency service said three new fires had broken out but were "not large-scale and not threatening".

"The radioactive background in Kiev and the Kiev region is within normal limits," Volodymyr Demchuk, director of the Emergency Response Department, said in a video statement.

He said more than 1,000 people were involved in trying to extinguish the fires.

But on Thursday new fires broke out, fanned by heavy winds that have made it harder to extinguish the blazes, Ukrainian officials said. Officials said, though, that the new fires were “not life-threatening.”

Andriy Budych walks near where he burned garbage and grass. The blaze then spread to the Chernobyl Exlusion Zone, in the village of Rahivka, police say. Oksana Parafeniuk / for NBC News

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

So far, the fires have scorched more than 3,500 hectares (13 square miles) of forest. Within days, they destroyed ecosystems and abandoned villages, nearly reached the radioactive waste storage areas and burned close to Pripyat, where radiation levels are still high, Yaroslav Yemelyanenko, a member of the public council at the State Agency of Ukraine on Exclusion Zone Management, told Ukrainian media Monday.

Although Ukraine’s State Emergency Service and some radiation control think tanks say there has been no increase in radiation, either in the Chernobyl zone or in Kyiv, Ukraine’s air has been polluted by aerosols and carbon emissions, Zibtsev said.

But some of the those who have touched off the conflagrations are unrepentant. One of them, Andriy Budych, 27, a resident of Ragivka village in the Kyiv region, started a fire April 5 next to an abandoned farm. The fire quickly burned more than 5 hectares (12 acres) of forest and nearby fields and then spread to the Chernobyl Exclusion Zone, 30 kilometers (19 miles) away.

“I did that to get rid of the grass,” he said this week. “Chernobyl was already burning when I started my fire.”

He showed a reporter the apocalyptic landscape — a blackened field, some burned grass and deadwood, and the charred remnants of the farm.

Why did he start the fire?

“People do that every year to get rid of dry grass,” he said. “It is a tradition!”

Now he faces up to five years in prison for destroying wildlife, the Kyiv Oblast (province) police department reported on its website.

Budych is not alone. Two other residents of the nearby Zhytomyr region also started fires April 3, the State Emergency Service reported.

While Budych said he was following tradition, other villagers and farmers have more practical reasons to burn off the dead grass, Yaroslav Kardash, vice president of the Association of Farmers and Private Land Оwners of Ukraine, said.

A forest ranger with the Poliskyi Distrcit State Forestry Agency prevents the spread of a fire. Oksana Parafeniuk / for NBC News

“It’s a much easier way to start preparing the soils for a new season,” Kardash said. “Dry grass doesn’t let you start seeding the fields. It is not nutritious for your cattle on pastures and in the forests. So you have to get rid of it somehow. People chose the easiest traditional way to burn it.”

The practice is not limited to this region of Ukraine. Manmade fires have destroyed 75 square miles of land this year, the State Emergency Service reported. In April alone, firefighters extinguished 800 fires Ukrainians had started by recklessly burning grass and garbage, the service reported.

In Ukraine’s western Zakarpattia region, a man caused a fire last week that burned 22 acres of daffodils. And on April 3, a local woman caused a fire that burned 40 trees in the Kyiv region as she tried to exterminate foxes that were killing her chickens, the State Emergency Service reported.

And in the Zhytomyr region in northwest Ukraine, locals accidentally torched a village council building this month when they lost control of a fire they started to get rid of grass.

As for the Chernobyl area, Kateryna Pavlova, the acting head of the agency that oversees the area, said the government will be able to calculate damage only after firefighters extinguish the blazes.

She said last week that there had been no increase in radiation, either in the Chernobyl zone or in Kyiv. And a state agency called those who questioned the government data spreaders of fake news.

But Zibtsev said the government needs to say that radiation levels are normal to avoid spreading panic.

And specialists at Ukraine’s State Scientific and Technical Center for Nuclear and Radiation Safety support the government’s position.

So why do people in Ukraine keep burning the grass?

Because they’re used to it. Burning dry grass was legal in the Soviet era.

Even though the Ukrainian government now imposes fines for setting grass fires, some say the fines are too small. As of the beginning of this year, the fines were between $13 and $30.

Zibtsev said the government has paid little attention to the problem until recently, and should have increased the fines 100-fold to make people think twice.

But this year’s fires have prompted authorities to search for a solution. This week, the Ukrainian parliament voted to increase the fines to up to $230 for starting a fire in a village or a town — and up to $5,600 for starting a fire outside of towns and in forests.

But Zibtsev said increasing the fines is not enough.

“Our government likes to forbid but does not offer an alternative,” he said. Local governments must provide villagers with the resources and the equipment to get rid of grass in a way that does not harm nature, he said.

“It is also time to educate people,” he said. “Tell them about the damage they cause by burning the grass. They destroy wildlife. And release pollutants the dry grass near the towns and the exclusion zone contains.”

Oleh Derkach, the head of the National Ecological Center of Ukraine, said the burning must be stopped.

“Villagers still think that by burning the dry grass they destroy parasites, clean the areas and stimulate vegetation,” Derkach said told NBC News. “While in reality, every arson is a crime against humanity and nature. And we are not talking here only about air pollution, tremendous damage to our health and material losses. Those people destroy ecosystems as their fires kill animals, provoke erosion and much more.”

Reuters contributed to this report.