Kiev - More than a thousand firefighters were working in the radiation-contaminated Chernobyl exclusion zone on Sunday, the 34th anniversary of the nuclear disaster, amid a weeks-long effort to extinguish brush fires in the area.
Authorities have attributed the fires in the predominantly uninhabited Chernobyl zone and in other parts of Ukraine in recent weeks to strong winds and abnormally dry conditions after a winter that lacked significant snow cover.
Firefighters in the Chernobyl zone, who have been in action for the past three weeks, were focusing on Sunday on "containment of two cells" of smouldering trees and brush, the State Emergency Service said in a statement.
Environmental experts have feared that such fires could stir up radioactive ash, potentially blowing contamination-laden smoke to the capital, Kiev, about 100 kilometres south of the devastated Chernobyl power plant.
Federal authorities have attributed smokey air in Kiev in recent days to fires in the nearby Zhytomyr region, assuring that radiation levels in Kiev are within an acceptable range.
Background radiation in Kiev is "stable" and does "not exceed the permissible values," the State Emergency Service said on Sunday, echoing an assessment it has made over the past week.
A senior environmental official, Egor Firsov, said amid the beginning of the fires earlier this month that radiation in the Chernobyl zone was detected at 16 times higher than normal background levels.
The 1986 reactor meltdown and explosion at Chernobyl is considered the worst nuclear disaster in history. Dozens of people, particularly firefighters and other first responders, died as a direct result of the disaster.
"On this day we bow our heads to the blessed memory of those heroes who saved the future from the danger of radiation," President Volodymyr Zelensky said in a statement for the anniversary.
He also expressed "deep respect" for the firefighters and others currently working in the zone to "protect these lands from new natural disasters."