TOKYO, JAPAN - Japan's trade ministry said on Tuesday that three fires had been caused by overheating Apple iPod nanos, which it said could be due to a battery defect.

No one was injured in the three fires involving the music players made by Apple Inc (AAPL.O) but the government said in a statement Apple had reported two other cases where people had suffered minor burns.

Apple officials were not immediately available for comment but the ministry said the firm had said a possible defect in iPod nano battery cells could have caused them to overheat.

The trade ministry said iPod nanos with known overheating incidents were sold in Japan between September 2005 and September 2006.

A semi-governmental body specializing in product safety will look into the cause of the incidents in cooperation with Apple, a trade ministry official said.

"We are not in the position to speculate on the outcome of the investigation. But after several incidents like these, it would be appropriate for Apple to take some measures to raise the public's awareness," the official said. --REUTERS