A Tokyo court yesterday rejected a compensation suit from Chinese victims of Japan's notorious World War II germ-warfare unit.
The High Court decision is the latest in a long line of similar rulings but comes amid a row between the two nations over their wartime history.
The judge acknowledged that the Japanese imperial military had engaged in germ warfare, said a lawyer for the plaintiffs, Jun Ogino.
"This is an unfair ruling that rejected compensation, although it acknowledged the facts," Ogino said outside the courtroom.
Their head lawyer, Kohken Tsuchiya, said: "We will appeal to the Supreme Court. We will fight to the end."
The lawsuit was brought by 180 Chinese plaintiffs who said they were survivors or relatives of the victims of germ warfare in Zhejiang and Hunan provinces from 1940 to 1942.
They wanted an apology as well as damages of 10 million yen (US$90,000 dollars) each from Tokyo for atrocities carried out by Unit 731 -- including bombing cities with plague, cholera and other germs.
In 2002 the Tokyo District Court had rejected their claim on the grounds that compensation is agreed between states and not individuals.
However the presiding judge had also recognized in that case that the Japanese military had engaged in germ warfare.
The ruling came as no surprise. In April, the same court rejected a separate compensation lawsuit filed by victims of Unit 731 together with survivors of the 1937 massacre in the city of Nanjing.
The latest lawsuit comes amid rising tensions between Japan and China in recent months over memories of Japan's bloody 1931-1945 occupation.
China, which has refused compensation from Japan for the occupation, accuses Japan of whitewashing its past. Tokyo in April approved a textbook that makes little mention of atrocities such as the Nanjing Massacre.
Unit 731 was set up in Manchuria after Japan formed a puppet state in northeastern China in 1931.
The secret military medical unit, disguised as a water purification bureau, engaged in biological warfare through human experiments, "bombing" Chinese cities with bubonic plague and other diseases.
The Japanese government denied the existence of Unit 731 until 1998, when the Supreme Court indirectly acknowledged it by ruling that there was an academic consensus that Unit 731 existed.
However, the government says it knows nothing about the unit's specific wrongdoing and has rejected related damages claims.