A man holds placards protesting sexual violence by US troops during a demonstration in Tokyo over the killing of a woman in Okinawa, allegedly by a US Marine. (AFP pic)

TOKYO: A woman's murder allegedly committed by a US Marine in Okinawa has triggered public outrage, prompted Japan's premier to slam a "heinous crime" and rekindled controversy over the heavy military presence on the southern island.

Here are five things to know about the latest case and Okinawa's thorny relations with the US military bases.

What happened?

Police said Sunday that a US Marine stationed on Okinawa was arrested on suspicion of killing a 39-year-old woman at a hotel in the city of Naha and stealing her wallet.