Ukraine is holding commemorations to mark the 30th anniversary of the nuclear disaster in Chernobyl, the BBC reports.
Sirens were sounded at the same moment as the first explosion at the reactor, in the early hours of 26 April 1986.
The meltdown at the plant remains the worst nuclear disaster in history.
An uncontrolled reaction blew the roof off, spewing out a cloud of radioactive material which drifted across Ukraine’s borders, into Russia, Belarus and across a swathe of northern Europe.
The relatives of those who died attended candle-lit vigils at several churches, including in the capital Kiev and in Slavutych, a town built to re-house workers who lived near the nuclear plant.