Thousands of Japanese people have staged a demonstration to express their strong opposition to the presence of USinfo-icon military bases on the southern island of Okinawa, and to demand the removal of the controversial sites and US Marine Corps from the region.

The protesters gathered at a seaside resort in the city of Nago in the northern part of the island on Thursday as the US military returned 9,800 acres of land it had controlled since the end of the Second Worldinfo-icon Warinfo-icon.

The demonstrators carried banners that read "Get out! Marines" and "No base Henoko" in English, as lines of policemen wearing masks stood by.'The protest rally came on the second day of joint US-Japaninfo-icon ceremonies held in Tokyo and Nago to mark the return of the land.

US Ambassador to Japan Caroline Kennedy, Japan's Chief Cabinet Secretary Yoshihide Suga, Japanese Defense Minister Tomomi Inada, US Forces Japan Commander Lieutenant General Jerry P. Martinez and other officials attended the Thursday ceremony in Nago.

Despite the return of the land used as a training camp for American forces, the US military is expected to continue to control the area. The Japanese government will reportedly construct six helicopter landing zones and a series of access roads there for US military training purposes.

Meanwhile, the Okinawa Prefectural Assembly passed a resolution on Thursday to oppose the resumption of Osprey flights after an aircraft broke apart upon impact in shallow waters off Nago.

"One wrong move could have led to a disaster involving residents," the resolution said.

A total of 24 multi-mission, tiltrotor Bell Boeing V-22 Osprey military aircraft are deployed at the Futenma air base in the crowded Ginowan city.

The Japanese and US governments have pursued the relocation of the Futenma base to the less populated Henoko coastal area of Nago, saying the plan is "the only solution" to address noise problems and accident risks.

Onaga and many other Okinawans, however, want the base to be relocated outside the prefecture.The disagreement between the central and prefectural governments has soared into a legal battle.

On Tuesday, the Supreme Courtinfo-icon ruled against the governor's attempt to block construction work in the coastal area.

The US military presence in Japan exceeds 100,000 people, with about half of the US troops deployed in Okinawa, according to US Forces Japan.