A candidate pledging to resist construction of a new US military base on the Japanese island of Okinawa has won the election for governor of the strategic island, local media said Sunday.

Both national broadcaster NHK and the Asahi Shimbun said Denny Tamaki had won Sunday's vote, in a blow to Prime Minister Shinzo Abe whose ruling Liberal Democratic Party (LDP) had backed a rival candidate.

Tamaki has vowed to continue fighting against a joint US-Japanese project to move the US Marines' Futenma Air Station from an urban area in Okinawa to a sparsely populated region of the island.

Abe's party backed Atsushi Sakima, who focused on economic messages throughout the campaign and stayed tight-lipped on his views about the base.

The LDP has long pressed Okinawa to accept the new air base. But opponents say the island already has more than its fair share of US military facilities and the base should be relocated outside Okinawa altogether.

The election was sparked by last month's death due to cancer of governor Takeshi Onaga, who also opposed the new base.

Tamaki, son of a US Marine who previously served as a national opposition lawmaker, cast himself as Onaga's rightful successor.

Okinawa accounts for less than one percent of Japan's total land area, but hosts about 28,000 US troops -- more than half of the approximately 47,000 American military personnel stationed in Japan.

Noise, accidents and crimes by US military and service members have long frustrated local residents, while municipalities in the rest of the nation have refused to share Okinawa's burden.

Onaga had tried to block efforts to reclaim land for the new offshore facility, and he and the national government filed rival lawsuits to try to settle the issue.

The Supreme Court ruled in favour of the government.

But a series of polls showed the majority of Okinawan residents remained firmly against the government's base plan.

Many residents voted early due to a powerful typhoon that rocked the island on Saturday, causing minor damage and dozens of slight injuries before it went on to batter the Japanese mainland on Sunday.