Ukraine has held memorial services to mark the 30th anniversary of the Chernobyl nuclear disaster, which permanently poisoned swathes of eastern Europe and highlighted the shortcomings of the secretive Soviet system.
In the early hours of April 26, 1986, a botched test at the nuclear plant in then-Soviet Ukraine triggered a meltdown that spewed deadly clouds of atomic material into the atmosphere, forcing tens of thousands of people from their homes.
Relatives of those who died as a result of the world's worst nuclear accident attended a candle-lit vigil in a Kiev church, built in their memory.
"We did not think that this accident would change all our lives, dividing them into 'before the war' and 'after the war' as we called it. It was silent nuclear war for us," said Lyudmila Kamkina, a former worker at the plant.
Others gathered for a service in Slavutych, a town 50km from Chernobyl that was established to house many of those who had to leave their homes for ever.
More than half a million civilian and military personnel were drafted in from across the former Soviet Union as so-called liquidators to clean-up and contain the nuclear fallout, according to the World Health Organisation.
Thirty-one plant workers and firemen died in the immediate aftermath of the accident, most from acute radiation sickness.
Over the past three decades, thousands more succumbed to radiation-related illnesses such as cancer, although the total death toll and long-term health effects remain a subject of intense debate.
The anniversary has garnered extra attention due to the imminent completion of a giant 1.5 billion euros (NZ$2.46 billion) steel-clad arch that will enclose the stricken reactor site and prevent further leaks for the next 100 years.
The project was funded with donations from more than 40 governments. Ukrainian Prime Minister Volodymyr Groysman said lessons learned from Chernobyl should be heeded all over the world.