Japan's Defense Ministry is ramping up construction on a controversial US military facility in Okinawa. Work is now underway on a new part of the planned site.
Workers have been pouring sand and dirt into the sea to reclaim land off the coast of Nago City.
But there is strong local opposition to the plan. In a non-binding referendum last month, a majority of voters opposed the landfill work.
Protesters rallied against it once again. A woman said, "It's totally unacceptable. The decision of the people of Okinawa is being completely ignored."
The Japanese and US governments want to relocate the US Marine Corps Futenma Air Station from an urban part of the prefecture to a less populated coastal one.
But the Okinawa government wants the base moved out of the prefecture altogether.
Around 70 percent of American military facilities are concentrated in Okinawa. Residents say they shoulder a disproportionate burden.
Local officials reiterated that the work should be scrapped. Okinawa's Vice Governor Kiichiro Jahana said, "The project hasn't won the people's understanding, which is why 72 percent of them opposed it in the referendum. We have to stop the work and hold dialogue."
The central government says it will stay the course with the relocation work.
Chief Cabinet Secretary Yoshihide Suga said, "We'll keep trying to gain understanding and cooperation from the local residents. But we will proceed with the work, giving due consideration to the natural environment and people's living environment, in line with the relevant laws."
Defense officials say they want to complete the current landfill work by the summer of 2020.