Mysterious metal ball found on Japanese beach causes bomb scare

Investigators examined the rusting metal orb with an X-ray device

The mysterious ball on a beach in Hamamatsu, Japan. Reuters.

A large, yellow metal ball washed up on Enshuhama beach in Japan, prompting a flurry of online speculation as to what the mysterious orb may have been used for.

Authorities dismissed the possibility that it could be a sea mine, after X-raying the device and finding that it was hollow.

On Wednesday, authorities went to inspect the object, which has a diameter of 1.5m, cordoning off a section of the beach because of fears it could be an unexploded war remnant or a mine that had drifted far from an active conflict zone.

Russia and Ukraine have each used mines in the Black Sea, while some countries still consider sections of their coastal waters dangerous because of unexploded naval mines from the Second World War.

Estonia believes there may be thousands of unexploded mines from the Second World War that could still pose a risk to shipping and, in 2018, a harbour at Brownsville, Washington state, was briefly closed due to fears that a mine had been discovered. Army engineers later said it was an inert device used for training.

Online speculation has led many to believe that the as-yet-unidentified object is a buoy that has escaped its mooring, a somewhat less exciting explanation than that of conspiracy theorists who say it may be an alien device.