A group of people in Japan's Okinawa Prefecture have filed suit to annul its governor's approval to reclaim an area for building a US military airfield.In December, Governor Hirokazu Nakaima approved the central government's plan to reclaim a coastal area of the Henoko District of Nago City in Okinawa. The approval was needed to build the airfield there to replace the US Marine Corps Futenma Air Station in Ginowan City, also in Okinawa, according to Japan's (NHK WORLD) website.The 194 plaintiffs include five residents of Henoko. They say the governor's approval is illegal and that the plan lacks measures to reduce aircraft noise and protect the local fishing industry and natural environment.They also requested a court injunction to temporarily suspend the validity of the approval in order to stall the project during the trial.The plaintiffs' leader Hiroshi Ashitomi says protecting the rich and beautiful nature of the sea, rather than building a US base, will benefit Okinawa.He said they will reverse the governor's judgment by asking him whether he has closely studied the landfill plan.