As of 21.30 local time (12.30 GMT), 5.59 percent of the votes were counted. More than 23,000 people (about 70 percent of counted ballots) voted against the construction of a new US base and only 8,000 people supported it. Another 2,000 people refrained from responding yes or no.
According to the exit poll, over one-quarter of the referendum's participants voted against the new US base, which gives grounds for Okinawa governor Denny Tamaki to convey the will of local residents to the governments of the United States and Japan.
The ballot reportedly asked citizens whether they backed a plan to reclaim land at a secluded coastal site for the relocation of the Futenma base from its current place in a heavily populated part of Okinawa.
READ MORE: Japan to Promote Relocation of US Base in Okinawa Regardless of Referendum
The US Marine Corps base Futenma was constructed in 1945. Talks on its relocation to a less populated area within the Okinawa prefecture started over two decades ago, but the government's plans have been hampered by local residents' protests.