Japan's government and the city of Hiroshima have appealed a court ruling ordering them to certify dozens of people who were exposed to radioactive "black rain" in the aftermath of the 1945 US atomic bomb attack.
The appeal comes after the Hiroshima District Court for the first time on July 30 recognised the "black rain" victims outside of a government-set physical boundary used as a basis for deciding survivors' eligibility for medical benefits.
Both the city and the prefectural government joined the appeal.
Health Minister Katsunobu Kato said on Wednesday that the government appealed because the ruling was "not based on sufficient scientific evidence."
Kato said, however, that his department will start its own scientific examination to consider expanding the "black rain" zone in Hiroshima to address the request from city and prefectural officials.
The court ruled that 84 plaintiffs who were outside the zone had developed radiation-induced illnesses and should be certified as atomic bomb victims.
The US dropped the world's first atomic bomb on Hiroshima on August 6, 1945, killing 140,000 people and almost destroying the entire city.
A second US atomic attack on Nagasaki killed another 74,000 before Japan's surrender on August 15, ending World War II.
The Hiroshima plaintiffs were in areas northwest of ground zero, where radioactive "black rain" fell hours after the bomb was dropped.
They have developed illnesses such as cancer and cataracts linked to radiation after they were exposed to the rain, not only that which fell but also by consuming water and food in the area that was contaminated.
The plaintiffs and their supporters asked Hiroshima not to appeal. City officials had indicated their intention to accept the ruling, but Mayor Kazumi Matsui said Wednesday that they could not reverse the government decision to appeal.