Japan is mystified by a giant metal sphere that washed up on a beach, with some commentators suggesting it's Godzilla's egg

• A metal sphere, 5 feet in diameter, washed up on a Japanese beach and has mystified authorities.
• The hollow ball is not explosive, and it could be just a buoy, authorities said.

A mysterious iron sphere that washed up on a Japanese beach has baffled authorities and sent social-media users into a frenzy.

The metal ball is about 5 feet in diameter and recently appeared on Enshuhama Beach in the coastal city of Hamamatsu, NHK, a state broadcaster, reported.

A passerby reported it to police on Saturday, which prompted an inspection, but a local man told the outlet that the ball had sat there for more than a month, the outlet said.

The beach was subsequently cordoned off, with officials in protective clothing sent to inspect the object.

Masaki Matsukawa, a representative of the city's civil-engineering office, told NHK that the rust-pocked object had still not been identified. The office said it could be a buoy, the outlet reported — an explanation supported by the presence of two apparent metal handles sticking out of it.

But on the tail of the media attention around Chinese spy balloons, the object has sent social media users into a flurry of speculation.

Some quickly suggested that it's likely one of the orbs from the popular manga series "Dragon Ball." Others disagreed, saying it's clearly a reptile egg readying to birth Godzilla.

A bomb-disposal team was dispatched and, after performing an X-ray, established that there's no risk of explosion, NHK said.

The sphere was scheduled for removal on Wednesday and will be stored in case someone comes to claim it, NHK reported. The BBC confirmed its removal in a report on Thursday.

"It could be confused for a World War 2 mine ... but those would have spikes sticking out of them," Mark Inall, a professor and oceanographer at the Scottish Association for Marine Science, told the BBC. He added that he immediately recognized the sphere as a buoy.

"Given the recent events ... I could understand there's an interest in an unidentified floating object," he added.