Korean Air, South Korea's largest airline, has banned the in-flight use of all of Dell and some Apple laptop computer models while operating on battery power after the U.S. firms announced massive recalls over a battery problem, a company official said Wednesday.

The ban has been in place since Aug. 30, but passengers can still operate the laptops if using electricity from the in-seat power supply system after separating the batteries from the computers, a Korean Air Co. spokeswoman said on condition of anonymity, citing policy.

The official said it's unclear when the ban would be lifted.

Dell announced a recall in mid-August of 4.1 million potentially flammable batteries supplied by Sony Corp. for laptop computers. Apple also recalled 1.8 million Sony-built notebook batteries later that month for the same reason.

The Korean Air ban covers all Dell laptops, and Apple's iBook and PowerBook computers.