Three airlines flying out of Shanghai are making passengers disconnect their Dell and Apple laptop batteries because they may catch fire.

Korean Air, Qantas and Virgin Atlantic have banned some or all of the batteries and ask owners to use in-cabin power supplies during flights.

No other airline has announced restrictions on laptops.The restrictions come in response to a recall of millions of batteries made by Sony. The recall affects only some Apple and Dell computers.

According to the Korean Air Website, all Dell laptops and Apple's iBook and Powerbook models must have their batteries disconnected before owners board planes.

The airline's hotline said yesterday passengers must hand in their batteries at check-in, and retrieve them from staff at their destination.

Korean Air does not provide external laptop power on routes from China to South Korea because flying time is less than two hours, the hotline said.

Virgin Atlantic said their passengers must disconnect all Dell and Apple laptop batteries and stow them in their luggage.

A company statement said the restrictions were the "result of the current problems being experienced by Apple and Dell with some of their batteries fitted to some of their laptops, as a safety precaution and with immediate effect."

All first-class passengers, and parts of business-class have access to external power supplies, the company said, though "only several" economy class passengers could use power lines.

Qantas allows Apple laptop batteries to be used on flights but asks Dell owners to disconnect theirs and stow them with their luggage. The airline provides external power supplies in first and business classes but not in economy, the carrier said.

Virgin Atlantic operates flights between Shanghai and London, while Korean Air operates flights from more than 10 Chinese cities, including Shanghai, to South Korean destinations including Seoul, Busan and Jeju. Qantas flies from Shanghai and Beijing to Sydney and Melbourne.

Kevin Yang, who works for a car company and flies more than 10 times a month, said yesterday, "I can't tolerate the flight without my computer and I will change the air carrier to make sure I can use a laptop."

Dell and Apple announced last month the recall of 6.1 million batteries because of fears they may overheat and go on fire.

Four Dell computers overheated because of the defect.