TOKYO (AP) - Japanese authorities reported Tuesday the first case of an Apple laptop catching fire in Japan and ordered the company to investigate the trouble involving the faulty Sony batteries and report back within a week.A laptop made by Apple Computer Inc. overheated and caught fire in April, the Ministry of Economy, Trade and Industry said. The user sustained minor burns after the iBook G4 computer caught fire, according to Apple spokeswoman Michiko Matsumoto, who confirmed the case. Last week, the Calif.-based company told its customers to return 1.8 million iBook G4 and PowerBook G4 batteries worldwide that could cause their laptops to overheat and catch fire, just 10 days after Dell recalled 4.1 million faulty laptop batteries for the same reason. In both cases, the problematic lithium-ion batteries were made by Sony Energy Devices Corp., a subsidiary of Sony Corp. based in Japan. Apple has received nine reports in the United States of the batteries overheating, including two consumers who received minor burns after handling overheated computers. Apple has also received reports of minor property damage, but no serious injuries have been reported. Japan's trade ministry ordered Apple's Japan branch to report on its findings and measures to prevent future troubles by Sept. 5 or it could face a fine of up to $2,570 under Japan's consumer safety laws. Sony and Dell also have been ordered to report on their findings after the recall was announced by the ministry. The trade ministry has also instructed other Japanese electronic makers to check the safety of their laptop batteries.