Two elderly protesters have been hurt trying to block trucks from entering Camp Schwab in Okinawa Prefecture, near the construction site of a bitterly contested American base.

Fumiko Shimabukuro, 85, was knocked to the ground during a scuffle with members of the Okinawan Prefectural Police who had been escorting the trucks into the base on Thursday. She was treated for a mild concussion.

A second activist, Masato Nakamine, 63, said he was left black and blue after being dragged along by a truck on Friday and then manhandled by "seven or eight" police officers in riot gear.