Ukraine has begun construction of a new protection shell over the damaged reactor at the Chornobyl nuclear power plant.
The work to replace the existing shell, which is crumbling and leaking radiation, comes on the 26th anniversary of the world's worst civilian nuclear disaster there.
The new shelter, weighing 20,000 tons, is due to be completed by 2015.
Speaking in a ceremony marking the start of construction, Ukrainian President Viktor Yanukovych thanked international donors for pledging a reported $980 million to build the new shelter and a nuclear fuel waste facility.
"I am pleased to say that Ukraine was not left alone to face the tragedy," he said. "We saw the whole world coming to help us."
The biggest donors are the Group of Eight leading industrial nations -- including Japan, which itself is still dealing with the effects of the Fukushima nuclear power plant disaster, triggered by the March 2011 earthquake and tsunami.
Yanukovych: State's Obligation
Fire and an explosion at one of Chornobyl's reactors on April 26, 1986, caused radiation to spread across parts of Ukraine, Belarus, and elsewhere in Europe. Dozens of workers died in the cleanup effort following the catastrophe.
Yanukovich said 2 million people have been affected by the Chornobyl nuclear accident and that it was the state's obligation to protect and treat them. The government, however, cut social benefits last year for survivors of the Chornobyl cleanup effort.
Hundreds of Chornobyl veterans – cleanup workers as well as victims of radioactive fallout – staged an angry protest in Kyiv with their supporters on April 26, demanding an increase in compensation and pensions.
Some 2,000 people gathered in front of the government headquarters while around 500 picketed the Ukrainian parliament, demanding their social allowances be paid in full.
After the 1986 accident, many of the power plant workers were relocated to the town of Slavutych -- about 50 kilometers from the Chornobyl plant -- leaving much of the radiation-contaminated area around Chornobyl abandoned.
Residents of Slavutych gathered on the town's main square on the night of April 25 to remember the victims. People holding candles and lanterns were led by a priest in prayer before they placed candles and flowers near the guard of honor memorial in the square.
Vladimir Sherbina, who worked at the plant at the time of the accident, said he came to the event to remember those who lost their lives and to pray that a similar disaster never happens again.
"The people who we remember today -- they paid for this mistake with their own lives," Sherbina said. "I hope this will never be repeated. And God forbid the people in charge of Chornobyl today repeat the mistake that was made by those in charge at the time of the Chornobyl accident."
The last of the plant's reactors was shut down in 2000. The process to decommission the plant, however, is expected to take decades.
With reporting by AP, Reuters, UNIAN, and RFE/RL's Ukrainian Service