Allegations that a drunken U.S. airman broke into an apartment in Okinawa and belted a teenager have heightened local calls for the bilateral accord protecting the rights of American service members in Japan to be amended.

The incident occurred less than three weeks after the arrests of two U.S. sailors for allegedly raping a woman in the city of Okinawa. The prefecture has long hosted the bulk of U.S. military facilities and personnel stationed in the country.

Following the sailors' arrests, the U.S. military in mid-October took the unusual step of introducing a nightly curfew on all personnel at its bases to improve discipline and avoid further damaging incidents. But the airman's alleged home invasion and assault in the early hours of Friday morning suggests the move has failed to serve its purpose.