Crowds are gathering on the Japanese island of Okinawa to protest against the heavy US military presence there.

Demonstrators are angry after a former US Marine employed as a civilian worker was arrested over the rape and murder of a local 20-year-old woman.

The case has intensified longstanding opposition to the military bases, spurring calls for US military personnel to be moved off the island.

Okinawa hosts 26,000 US military personnel.

They work and live on bases that cover a fifth of the island and are a key part of the US-Japan security alliance.

The protestors will rally in the prefectural capital Naha, with a simultaneous gathering due to happen outside parliament in Tokyo in sympathy.

Okinawa's Governor Takeshi Onaga is expected to attend the Naha rally.

The demonstrators will also call for the scrapping of plans by Washington and Tokyo to move a major US Marine facility in the centre of the island to a more remote area.

But Mr Onaga and residents want the Futenma base to be removed entirely.

The decision to move the facility was sparked by the rape of a 12-year-old Japanese girl by three US servicemen in 1995.

But the plan has been delayed by local opposition and legal manoeuvring.

Okinawa was under US occupation for 27 years, following World War Two.