Residents and groups filed a lawsuit Wednesday with the Yokohama District Court to confirm the illegality of the Yokohama mayor's failure to retrieve part of the land used by a U.S. Navy communications facility.

According to the suit filed by 130 Yokohama residents and 22 organizations, about 22.6 hectares of the roughly 242 hectares of the Kamiseya communications facility belong to the city of Yokohama.

Under an agreement, the Yokohama Municipal Government had leased the tract to the national government, which has provided it to the U.S. military since 1978, according to the suit.

The plaintiffs charge that the U.S. Navy facility has not been needed since the end of the Cold War and after the development of new communications technology, and that the property has stood idle since 1995.

Yokohama Mayor Hiroshi Nakada has been remiss in his duty to control municipal assets, as he is obliged to dissolve the contract and request the return of the land from the United States, according to the plaintiffs.

In connection with the facility, the owner of the land has filed a suit against the national government and the U.S., seeking a return of the land. The Yokohama District Court is scheduled to rule on that case Aug. 29.