A magnetic anomaly that was found at Miyazaki Airport following an explosion of a U.S. World War II bomb was confirmed to have been caused by a large amount of iron sand.   

An explosion occurred on the taxiway at the airport on October 2 about a minute after a passenger plane passed by.  

Officials found a magnetic anomaly during their investigation of the explosion and suspect this has something to do with the explosion.

On October 19, the Ministry of Land, Infrastructure, Transport and Tourism dug up the site and found that the magnetic reaction was caused by a large amount of iron sand.

Ministry workers filled the area after confirming safety, and the airport resumed operations on October 20 at 7:30AM. 

Some of the first flights at Miyazaki Airport were cancelled due to this work, but flights have been operating normally since then.