The people of Okinawa are voting on a plan for a U.S. military base relocation in a referendum that will send a message on how they feel about housing American troops in Japan.

The referendum is technically not binding but interest is high for testing the public sentiment about the plan to relocate Futenma air base.

The plan has its beginnings in 1995, when outrage erupted against U.S. service members over the rape of a 12-year-old girl. Futenma was long criticized as dangerous, being in a residential area.

A replacement base is on coastal landfill in an area called Henoko. Critics say wildlife such as coral reefs and the dugong, will be hurt.

About 1.16 million residents are eligible to vote.