The latest incident on Okinawa has triggered memories of the 1995 rape of a 12-year-old schoolgirl by three US servicemen that sparked huge protests on the island and raised concerns about damage to the broader security relationship.
The US ambassador to Japan, Thomas Schieffer, flew to Okinawa this week in an effort to soothe anger over the episode, which comes as Tokyo tries to persuade Okinawa residents to accept a plan to move the Marines' Futenma air base from the crowded city of Ginowan to the coastal city of Nago, part of a broader plan to move about 8,000 Marines from Okinawa to Guam.
On Thursday, the top commander of the US forces in Japan told reporters the military had set up a task force to review and strengthen programs to prevent sexual harassment and assault.
"It is our job to do everything we can to restore the confidence of the Japanese people in the US forces stationed here in Japan," Lieutenant General Bruce Wright said.
Last Sunday, the mayor of Iwakuni city lost a re-election bid he had hoped would give him a mandate to battle on against a US-Japan plan to expand a US Marine base in the city.
