Women wearing face masks to protect against coronavirus ring the church bells at a memorial of the Chernobyl tragedy victims in capital Kyiv, Ukraine, April 26, 2020.
Women wearing face masks to protect against coronavirus ring the church bells at a memorial of the Chernobyl tragedy victims in capital Kyiv, Ukraine, April 26, 2020.

The United Nations says persistent and serious long-term consequences remain more than 30 years after the explosion and fire at the Chernobyl nuclear power plant in Ukraine.

The world body is marking International Chernobyl Disaster Remembrance Day on April 26, the 34th anniversary of the accident that spread a radioactive cloud over large parts of Belarus, Ukraine, and Russia.

The anniversary is being marked after fires recently burned in the 30-kilometer exclusion zone around the plant, raising concerns about the potential release of radioactive particles into the air.

In this photo taken from the roof of Ukraine's Chernobyl nuclear power plant on April 10, 2020, a forest fire is seen burning near the plant inside the exclusion zone.

The U.N. General Assembly adopted a resolution in December 2016 designating April 26 as a day to recognize the consequences of the accident. Its statement says that while progress has been made, “there is still a great deal of work that needs to be done in the affected region.”

The United Nations says the completion of a confinement structure over the reactor most heavily damaged in the accident was a major milestone of 2019.

It noted that the project received more than $2 billion in funding from 45 donor nations through funds managed by the European Bank for Reconstruction and Development. The scope of the project in terms of international cooperation is one of the largest ever seen in the field of nuclear safety, the U.N. said.

A woman wearing a protective mask lights a candle at a memorial, dedicated to firefighters and workers who died after the Chernobyl nuclear disaster, during a night service in Slavutych, Ukraine, April 26, 2020.

The U.N.'s involvement in Chernobyl recovery efforts dates back to a resolution passed in 1990. U.N. agencies continue to work closely with the governments of Belarus, Russia, and Ukraine to provide development assistance to the communities affected by the disaster.

The U.N.'s statement on Chernobyl remembrance day does not mention the fires that have burned in the exclusion zone. The largest among several blazes was extinguished last week. Smaller fires continue to burn in the zone, the authority that administrates it said on April 24.

Video showing plumes of smoke billowing from the charred landscape earlier this month alarmed environmental activists, who said the burning of contaminated trees and other vegetation could disperse radioactive particles.

The International Atomic Energy Agency (IAEA) said on April 24 that the increase in levels of radiation measured in the country was very small and posed "no risk to human health."

The Vienna-based IAEA, which acts as the U.N. nuclear watchdog, said it was basing its assessment on data provided by Ukraine.

There have been "some minor increases in radiation," the IAEA said, adding the State Nuclear Regulatory Inspectorate of Ukraine found the concentration of radioactive materials in the air remained below Ukraine's radiation safety norms.