The world on Tuesday marks a quarter of a century since the world's worst nuclear accident at Chernobyl. The anniversary has added resonance after the recent Fukushima disaster in Japan.
Ukrainians lit candles to honor the victims of Chernobyl
Several ceremonies marked the 25th anniversary of the Chernobyl nuclear disaster in Ukraine on Tuesday, amid heightened fears over nuclear safety in the wake of recent events at Japan's Fukushima power plant.
Russian President Dmitry Medvedev visited the site of the Chernobyl accident on Tuesday to take part in a memorial service, and was joined by his Ukrainian counterpart, Viktor Yanukovych.
Together, they unveiled a foundation stone for a planned monument to be built in honor of Chernobyl's so-called "liquidators," some 150,000 men and women who worked to control the effects of the 1986 explosion at reactor number four.
"Humanity will always remember your sacrifices," President Yanukovych said at the ceremony, broadcast live on national television in both countries.
Medvedev also praised the liquidators' work, saying they helped keep the world's worst-ever nuclear accident under at least a modicum of control. Despite the dangers presented by Chernobyl and more recently Fukushima, the Russian leader said nuclear power remained an essential energy resource, because "no one has yet offered new sources of energy."
Belarusian President Alexander Lukaschenko, however, did not attend the main memorial service, electing instead to tour villages and scientific facilities in irradiated territories within his country.
A man remembers firefighters who attended the reactor
In the Ukrainian capital Kyiv, a bell tolled 25 times to mark the number of years that have passed since the accident.
In the early hours of April 26, 1986, workers at the Chernobyl atomic power station in the then Soviet Union were carrying out a test on reactor four when operating errors and design flaws sparked successive explosions.
Radioactive debris landed around the reactor, creating an apocalyptic scene in the surrounding area, while material also blew into the neighboring Soviet republics of Belarus and Russia and further into western Europe.
Moscow said nothing about the disaster for three days, with the official news agency TASS only reporting an accident on April 28, after the Forsmark nuclear plant in Sweden recorded unusually high levels of radiation.
Two workers were killed in the explosion and 28 other people died of radiation exposure in the next months. Tens of thousands were forced from their homes and many suffered long-term health effects. The exact death toll is disputed; some estimates suggest it runs into the thousands.
Russian President Medvedev honored rescue workers who were exposed to high levels of radiation
Medvedev acknowledges past mistakes
Before unveiling the memorial to the Chernobyl liquidators, many of whom were not fully aware of the gravity of the situation they were braving, Medvedev told some of the survivors that the former Soviet Union could have handled the disaster better.
"I think that our modern states must see the main lesson of what happened at Chernobyl and the most recent Japanese tragedy as the necessity to tell people the truth," Medvedev told a meeting of liquidators in the Kremlin on Monday.
"The world is so fragile and we are so connected that any attempts to hide the truth, to gloss over a situation, to make it more optimistic, will end with tragedy and cost the lives of people."
Chernobyl cleanup veterans in Ukraine are also sometimes critical of their government, as some parliamentarians call for cutbacks in liquidators' health and social benefits to improve state finances.
"It is painful for me that the government is unable to thank you properly for your victory," President Yanukovych told the cleanup veterans on Tuesday. "But believe me, we will do everything possible to ease and improve your lives."
The 25th anniversary has gained contemporary resonance after this year's March 11 earthquake and tsunami in Japan which damaged reactors at the Fukushima nuclear power plant and prompted leaks of radiation. Along with Chernobyl, it's the only other disaster to be classed as level seven on the International Nuclear Event Scale.
Author: Joanna Impey, Mark Hallam (AFP, AP, dpa, Reuters)
Editor: Susan Houlton