Ukrainian authorities have called for calm as firefighters battle a blaze near the abandoned Chernobyl nuclear plant.
A senior emergency service official said there was “no threat” to the plant or its storage facilities, while deputy interior minister Anton Gerashchenko insisted: “Everything will be fine”.
But there are fears the fires have grown to a huge size.
Greenpeace Russia said one was just one kilometre from the plant itself.
The NGO’s Russia branch, quoted by Reuters, said the largest fire covered 34,000 hectares, while a second fire, just a kilometre (0.6 mile) from the former plant, was 12,000 hectares in area.
Though fires are common in the area, Greenpeace said this could be the worst in decades. Police have arrested a 27-year-old man and accused him of starting the blaze on 4 April.
In 1986, the former nuclear plant suffered a catastrophic meltdown that spread radioactive fallout across Europe.
Chernobyl and the nearby town of Pripyat have been abandoned ever since, although they have attracted large numbers of tourists in recent years.
What’s the situation?
Emergency services continue to battle the blaze. Ukraine has sent hundreds of firefighters as well as planes and helicopters.
Officials in Kyiv say there is no reason for alarm. In a post on Facebook, Mr Geraschenko called for “calm, only calm”, insisting the huge concrete structure built to cover up the former nuclear site was safe and that there was “no change” in radiation levels.
Efforts to contain the fire are complicated by the disaster, he said. Firefighters cannot dig deep trenches in the ground for fire breaks as “radioactive particles” could be exposed, but aircraft have instead dropped huge volumes of water on the fires.
“The task of rescuers is to prevent the spread of fire to critical infrastructure. And they will cope with this task!” Mr Geraschenko wrote. “Please do not interfere with their work. Do not spread fakes, untruth and nonsense. Everything will be fine.”
But others say the situation is far worse.
Sergiy Zibtsev, head of the Regional Eastern European Fire Monitoring Center, told AFP news agency that the fire had become “super-huge” and “unpredictable”.
Local tour operator Yaroslav Emelianenko said one fire had reached Pripyat, which used to serve the plant.
He said it was now just 2km (1.24 miles) from where the most dangerous waste from the plant was stored. “The situation is critical,” he wrote on Facebook.
Mr Emelianenko also said that if the fire engulfed Pripyat it would be an economic disaster, as supervised tourist visits provided valuable revenue.
In 2018 more than 70,000 people visited the town. Last year that figure was even higher, after the success of an HBO mini-series about the disaster.
Smoke from the fire is now blowing towards Kyiv.
Chernobyl nuclear power station and Pripyat have been abandoned since 1986, when the plant’s No. 4 reactor blew up.
People are forbidden from living within 30km (18 miles) of the power station.
Chernobyl continued to generate power until the plant’s last operational reactor was finally closed in 2000.