TOKYO (Reuters) - Police dragged away elderly protesters trying to block work on a contentious U.S. airbase in Okinawa on Thursday as Japan's government resumed building even though the Okinawa governor had revoked a work permit for the site.

Residents of Okinawa, the site of bloody battles near the end of World War Two, resent hosting any U.S. military at all, and oppose the government's plan to move the U.S. Marines' Futenma base to another location on the southern island.

Protests backing the stand taken by Okinawa have drawn tens of thousands of people, and perceptions of bullying by the government could dent support ratings for Prime Minister Shinzo Abe ahead of an election next year.

Two weeks ago, anti-base governor Takeshi Onaga, who has accused Abe of looking down on Okinawa, revoked the permit issued by his predecessor for key landfill work needed for the new base. But, the government ignored it, citing the need for "administrative continuity".

Roughly 100 protesters, many of them elderly, gathered early on Thursday to block the way for construction trucks and bulldozers, before police dragged them away.

One elderly woman with a cane yelled "Put me down!" as she was hauled off in a chair.

"What are you doing?" another white-haired woman shouted at police. "Aren't you supposed to be protecting citizens?"

Onaga told reporters that Okinawa would continue to resist.

"All I can sense is strong-arm governance, which is extremely unfortunate," he added.

The United States and Japan agreed in 1996 to close Futenma, located in a densely populated area that the central government says makes it one of the "most dangerous airports in the world", but plans to move it stalled due to opposition from Okinawa residents worried about noise, pollution and crime.

Tokyo reiterated that it intends to stick to the agreement.

"We in the government want to proceed with the Futenma move as soon as possible," deputy chief cabinet secretary Hiroshige Seko told a news conference.