The Okinawa Prefectural Government on Wednesday filed another lawsuit against the central government as it seeks to halt the ongoing landfill work for the relocation of a U.S. air base within the prefecture.

In the lawsuit filed with the Naha branch of the Fukuoka High Court, Okinawa is seeking to challenge the legality of land minister Keiichi Ishii’s involvement in a move authorizing the work to build a replacement facility for U.S. Marine Corps Air Station Futenma.

The central and Okinawa governments have been at odds over the relocation of the Futenma base from a crowded residential district in Ginowan to the less populated Henoko coastal area of Nago. In recent years, the feud has evolved into a legal battle.

Many residents in Okinawa Prefecture, which hosts the bulk of U.S. military facilities in Japan, have long hoped the Futenma base would be moved out of the prefecture.

The central government maintains that the relocation plan is the “only solution” for eliminating the dangers posed by the base, which is situated close to schools and homes, without undermining the deterrence provided by the Japan-U.S. security alliance.

The landfill work in the Henoko area was initially approved in 2013 by Gov. Hirokazu Nakaima. His successor, Takeshi Onaga, a staunch opponent of the plan who died of cancer in August last year, failed in his attempt to revoke the approval.

The Okinawa government then retracted its approval for the landfill work, saying some weak ground was found in the planned area to be reclaimed. Ishii voided the retraction in April this year.