The Japanese government has protested to the United States about an alleged incident involving a US marine on the island of Okinawa.

The marine was arrested by Japanese police on suspicion of attempted rape.

A junior foreign minister Yutaka Kawashima called on the Americans to tighten discipline among their forces based in Okinawa.

The alleged incident is the first since a four-year curfew on soldiers' night activities was lifted last October.

It was imposed by the American military authorities following the rape of a schoolgirl by three servicemen, which caused an uproar in Japan.

From the newsroom of the BBC World Service