Tens of thousands joined together Sunday in a massive protest against the presence of U.S. military bases on the southwestern Japanese island of Okinawa, where an American contractor and former Marine is accused of raping and killing a local woman.

The rally calls for a review of the U.S.-Japanese security agreement, which burdens Okinawa with hosting most of the U.S. troops in Japan. The murder set off outrage on Okinawa, where tensions periodically run high over crime.

The U.S. and Japan agreed in 1996 to close and relocate the Marine Corps Futenma air station after the rape of a 12-year-old girl by three American servicemen. The crime also spurred massive demonstrations about the U.S. presence on the island.

According to Reuters, the plan had been on hold since residents living at the proposed relocation site have protest against the move over potential noise, pollution and crime.

The island hosts 50,000 Americans, including 30,000 military personnel and civilians employed at U.S. bases. Okinawa remained under U.S. control after World War II until 1972 and about a fifth of the island is still occupied.

Though the murder marks a low point in relations between the U.S. and Japanese Prime Minister Shinzo Abe, the two sides are still working closely together to stunt China’s ever-growing growth in the East China Sea and the Okinawa island chain is a point of emphasis in military maneuvers.

Japan’s Self Defense Force is fortifying the region with radar and anti-missile batteries.

Last month’s arrest of a 32-year-old U.S. contractor working at an American military base, prompted the U.S. to announce a 30-day mourning period for the victim and restricted off-base drinking.