Immigration authorities on Wednesday placed 27 Chinese in custody on suspicion that they illegally entered and stayed in Japan by using fake certificates identifying them as offspring of Japanese women married to Chinese and left behind in that country after World War II, officials said.
The operation, in simultaneous raids in Tokyo and neighboring Kanagawa Prefecture, was the largest crackdown yet by authorities, who are trying to stem an increase in the number of illegal Chinese immigrants who take advantage of rules that allow the kin of these women to obtain residency status in Japan.
The Justice Ministry has been tightening control over these immigrants since 1997, mainly in the Tokyo and Osaka areas.