Some 190 residents of Okinawa Prefecture sued Wednesday to cancel Gov. Hirokazu Nakaima's approval of land reclamation work for a new U.S. military base.
In a suit filed with the Naha District Court, the residents charge the approval is illegal because the land reclamation plan fails to include sufficient environmental conservation measures.
They also asked the court to suspend the approval to prevent the reclamation work from beginning.
Last month, Nakaima approved the central government's plan to reclaim land off Henoko in the city of Nago for building a new base to replace the U.S. Marine Corps' Futenma Air Station in Ginowan city, having found the environmental measures sufficient.