Okinawa Prefecture on Sunday marked 50 years since its reversion to Japan from U.S. rule as residents' frustrations continue over a weak local economy and the ever-present U.S. military bases despite decades of protest.

At a commemoration ceremony held near a major U.S. military base on the island, Gov. Denny Tamaki urged the central government to undertake "sincere efforts" to make Okinawa "an island of peace," saying that the mutual goal made at the time of reversion remains unfulfilled.

"Even after 50 years ... the people of Okinawa continue to be forced to shoulder excessive base-hosting burdens," Tamaki said in his speech, citing accidents and crimes involving U.S. troops as some glaring examples of the cost.