TOKYO, JAPAN - An iPod nano in Japan overheated and discharged sparks, the Japanese industry ministry said Tuesday in a list of recent serious incidents involving consumer products.

"The battery part of the product overheated while being charged and sparked," the ministry said, adding it was investigating the January 8 incident.

Makers Apple in Japan could not be reached immediately.

The company has publicly warned that iPod, iPod nano or iPod shuffle may generate excess heat while being charged in certain carry cases. --AFP