Forty-five Japanese atomic bomb survivors sued the government Thursday over its refusal to grant them radiation victim status.
They are seeking a revocation of the government's decision and 3 million yen each in compensation.
The suits filed in Nagasaki, Hiroshima and Kumamoto district courts follow similar suits brought by a total of 28 plaintiffs in Sapporo, Nagoya and Nagasaki on April 17, and in Tokyo, Chiba and Osaka on May 27.
Ten other plaintiffs are to join in the lawsuit in Hiroshima in August.
The Japan Confederation of Atomic and Hydrogen Bomb Sufferers Organizations (Hidankyo) said it aims to involve 100 plaintiffs in the suits and bring about changes in government policy on atomic bomb sufferers.
According to the suits, the plaintiffs were exposed to radiation in Hiroshima and Nagasaki in August 1945 and have suffered from cancer and liver disease.
They have asked the government to recognize them as radiation illness victims, but were rejected. The status would entitle them to special medical benefits.
The plaintiffs' lawyers aim to demonstrate links between the A-bomb radiation and the illnesses.
As of the end of March last year, 285,620 people had certificates recognizing them as atomic bomb survivors.
Of those, only 2,169, or 0.76 percent, are recognized as suffering from radiation illnesses, according to the Health, Labor and Welfare Ministry.