Chernobyl nuclear disaster: Ukraine marks anniversary
Ukraine is marking the 25th anniversary of the world's worst nuclear accident - at the Chernobyl power plant.
An explosion at one of the plant's reactors sent a plume of radiation across Europe and killed at least 30 people in its immediate aftermath.
A disputed number of others died later from radiation-related illnesses.
The anniversary comes amid renewed global protest over nuclear power and as Japan struggles to contain radiation leaks at its crippled Fukushima plant.
It was on 26 April 1986 that Number Four reactor at Chernobyl, which was then in the Soviet Union, exploded.
The accident forced the evacuation of hundreds of thousands of people from their homes in Ukraine, western Russia and Belarus.
There is still a 30km (19 miles) exclusion zone around the plant.
Soviet engineers encased the damaged reactor in a temporary concrete casing to limit the radiation but a new shield is needed.
A donors conference in Kiev, Ukraine, last week raised 550m euros (£486m; $798m) of the 740m euros needed to build a new shelter and a storage facility for spent fuel.
Soviet officials held off reporting the accident for several days.
The Chernobyl anniversary comes less than two months after the Fukushima nuclear plant in Japan was badly damaged by an earthquake and tsunami, renewing concerns about the safety of nuclear power generation.
The operators of the Fukushima plant, Tokyo Electric Power Co, have also come under fire for not quickly disclosing information on radiation leaks from the plant.
Russian President Dmitry Medvedev said there must be greater transparency in nuclear emergencies.
"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," he told survivors of the clean-up effort at a meeting in the Kremlin.
He is to visit Chernobyl on Tuesday, as is Ukraine's Prime Minister Viktor Yanukovych.
Mr Yanukovich and Russian Orthodox Patriarch Kirill were attending a candle-lighting ceremony in Kiev on Monday night before travelling to Chernobyl.
On Monday, thousands of people in France and Germany staged protests calling for an end to nuclear power.
Marches were held on several river bridges between France and Germany over the Rhine while there were further protests at German nuclear plants.
One of the main protests in Europe took place over the Pont de l'Europe, linking France and Germany over the Rhine between Strasbourg and Kehl.
People waved banners with anti-nuclear slogans and chanted: "Chernobyl, Fukushima, never again!"
As a siren wailed, the protesters threw flowers on to the Rhine and lay down on the pavement of the bridge in what they termed a symbolic "die-in".
Meanwhile in India, security has been tightened around Jaitapur, where protesters are planning to march on the site of a planned six-reactor nuclear power plant.
The campaign against the power station, on the west coast of India, has gained momentum since the disaster at Fukushima.BBC News