Japan is warning users of Apple iPod nanos of a potential fire risk, after two new instances in which the popular portable music players overheated and caught fire.

According to Japan’s Economy, Trade and Industry Ministry, Apple Computer has been notified of 14 similar cases in Japan. The ministry said the incidents were caused by four models, of which 1.81 million units were sold between September 2005 and September 2006 in Japan:

• MA004J/A
• MA005J/A
• MA099J/A
• MA107J/A

“Users need to be careful about overheating of the machines,” the Ministry said in a statement, warning that particular care is needed when recharging the iPods. “Our ministry told Apple to improve its technological development and probe the cause of the incidents so that similar incidents do not happen again.”

Apple has not responded offered an official response to the warning.

via Yahoo; image: Stephen Dinges