Minamata disease patients and relatives march in Tokyo. Hundreds marched on Saturday to press for more help for sufferers
Events are taking place in Japan in memory of victims of a condition caused by mercury poisoning, 50 years after it was first officially reported.
A memorial was unveiled in the southern town of Minamata on Sunday, while a commemorative service is due on Monday.
The condition, Minamata disease, has claimed 2,000 lives, but thousands more say they have been affected by it.
The neurological disorder is linked to eating fish from waters polluted by mercury dumped by a chemical firm.
About 1,000 people, including bereaved families and Japanese Environment Minister Yuriko Koike, are expected to attend Monday’s event on Kyushu island, the Japanese news agency Kyodo reports.
In addition to those who died, nearly 1,000 people have been officially registered as having the condition since it was first diagnosed in Minamata on 1 May, 1956.
In October 2004, the Japanese Supreme Court ruled that the government was partly responsible for those affected by Minamata disease.
Symptoms include spasms, blurred vision and deformity among babies of poisoned mothers.
On Saturday, hundreds of people with the disease and their supporters marched in Tokyo to pressure the government into further expanding help to sufferers.
In the past week, the Japanese parliament announced plans to provide health care and compensation to those not yet officially recognised as victims of the neurological disorder.
The small town of Minamata is now forever linked with mercury poisoning.
In the 1950s, local residents began complaining of numbness, slurred speech and strange behaviour.
Birds were seen literally dropping out of the sky and cats appeared to be behaving strangely.
By the late 1950s, the cause was apparent.
A local chemical manufacturer, Chisso, had been dumping mercury into Minamata bay.
This poisoned the fish, and then everyone and everything that ate the fish. By this point people were dying, and severe physical and mental side effects were being reported.
Nevertheless, Chisso continued to pump mercury into the sea until 1968, when the authorities finally declared that Minamata disease was a form of mercury poisoning.
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