Thousands of people rallied in Okinawa in southern Japan on Sunday in protest against a controversial US air base on the island, as the row over the relocation of the site drags on.

Okinawa is home to more than half of the 47,000 US service personnel stationed in Japan as part of a defense alliance, a proportion many islanders say is too high.

The US Marine Corps Futenma air base has become emblematic of that ill-will since Washington announced plans to move it in 1996, hoping to ease tensions with the host community after the gang-rape of a schoolgirl by servicemen.