SENDAI--Girls as young as 9 diagnosed with intellectual disabilities underwent forced sterilization under a postwar law aimed at "preventing the birth of inferior offspring."

Records kept by the Miyagi prefectural government for fiscal 1963 through 1981 show that 859 local residents were sterilized under the provisions of the old Eugenic Protection Law. Of that figure, 448 were minors.

For the full period when the law came into effect in 1948 through 1996, when it was renamed the Maternal Health Law, 1,406 residents of Miyagi Prefecture were forced to submit to sterilization.

The list includes the names, ages and reasons for the sterilization. Local authorities kept the records to ensure the central government covered the expenses for the procedures.

Boys as young as 10 were sterilized on two occasions, in fiscal 1965 and 1967, while two girls aged nine were sterilized in fiscal 1963 and 1974.

Yasutaka Ichinokawa, a sociology professor at the University of Tokyo who is knowledgeable about the issue, said, "Despite the fact that the old Eugenic Protection Law did not have provisions setting an age limit, I am very surprised that girls as young as 9 were forced to undergo sterilization."

Of the 859 individuals, 320 were male and 535 were female. The gender and age of four individuals were not included. Among the males, 191 were minors. Among the females, 257 were minors.

In total, 745 individuals were listed as having genetic intellectual disabilities.

According to a citizens group seeking an apology from the government, 16,500 or so individuals across Japan underwent forced sterilization.

For the bulk of the patients, however, details such as age, gender and reason for the procedure have not been disclosed.

Hokkaido had the most forced sterilizations at 2,593, while Miyagi Prefecture had the second largest number.

A woman in her 60s who was sterilized at 15 filed the first challenge to the constitutionality of the Eugenic Protection Law at the Sendai District Court on Jan. 30. She is seeking 11 million yen ($101,000) in compensation.

A group supporting her efforts has called on the government to establish a fund to provide compensation and fully disclose details of the forced sterilization program.

However, at a Jan. 30 news conference, Katsunobu Kato, the welfare minister, said, "We have heard directly from those who were affected based on their requests and we will continue to listen if such requests are made in the future."

He stopped short of promising a more extensive study.