in brief An iPod nano in Japan overheated and discharged sparks, the Japanese industry ministry said today.
"The battery part of the product overheated while being charged and sparked," the ministry said, adding it was investigating the 8 January incident.
Apple did not respond to requests for comment.
The company has publicly warned that iPod, iPod Nano or iPod shuffle may generate excess heat while being charged in certain carry cases.
Today's report comes after a spate of battery issues with handheld and other portable devices in the last twelve months, including a number of product safety recalls and other instances of batteries emitting sparks or exploding while charging.
Nokia in particular was plagued by reports of exploding batteries late last year, after it warned of oveheating problems associated with defective batteries in a number of its phone models
A number of other manufacturers -- including Apple -- have experienced similar problems with laptop batteries; ranging from recalls associated with overheating concerns, to reported cases of combustion.