Radiation killed thousands in the area, with the final death toll estimated between 9,000 and 90,000.
The city of Slavutych in northern Ukraine is commemorating the 33rd anniversary of the Chernobyl nuclear disaster. A unit of the power plant exploded in the early hours of April 26, 1986 and the resulting fire burned for nine days. The event remains the worst nuclear power plant accident in history.
Two plant workers were killed within the facility – one immediately in the explosion and the other in the aftermath by a lethal dose of radiation – and 28 firemen and plant employees died over the following months of acute radiation syndrome (ARS). Of the 134 people initially hospitalised with ARS, 14 died of radiation-induced cancers over the next ten years.
Slavutych was purpose-built as a replacement for the plant town of Pripyat, which lay 1.5 km from the Chernobyl plant and was home to its workers and their families, until it was abandoned in the wake of the disaster and its residents evacuated, never to return.
Some 50,000 Pripyat residents were installed in Slavutych, to be joined by those who subsequently arrived to work at the plant, which remained operational until December 2000.
Alyona Sheyderova, a former Chernobyl plant worker attending the vigil, said: "So many years have passed, but we still remember. You know, many people can't come here because they lived through it. My friends are from Pripyat. They've lived through it all. Evacuation, explosion, scattered families. They can't come here. It's too real for them.
"So the only thing I can do, the only thing we, people can do is to remember. To come here today and stay for a minute. Remember these people and thank them."
The final death toll of Chernobyl is subject to speculation due to the long-term nature of the effects of radiation, but generally ranges from an estimate of 9,000 by the World Health Organisation to 90,000 by the environmental campaign group Greenpeace.
Student Anastasia Murdinskaya said: "The world forgets. From one side it's good, because it's a tragedy and it shouldn't leave scars on souls, on the other side it's bad. Because people should know the history."