Boeing sent out an advisory to 15 airlines warning about a risk of engine icing problems on its new 747-8 and 787 Dreamliner planes with engines made by General Electric, urging them to avoid flying them near high-level thunderstorms.

The warning led Japan Airlines (JAL) to pull 787 Dreamliners from two international routes. Other affected airlines include Lufthansa, United Airlines, an arm of United Continental Holdings and Cathay Pacific Airlines.  Air Canada isn't flying any of the specially-designed Boeing planes at the moment but is expecting the delivery of six Dreamliners in 2014.

Boeing issued a notice Friday prohibiting the affected aircraft from flying at high altitude within 50 nautical miles of thunderstorms that may contain ice crystals.

Japan Airlines said on Saturday it will replace Dreamliners on its Tokyo-Delhi and Tokyo-Singapore flights with other types of aircraft while also dropping a plan to use 787s for its Tokyo-Sydney route from December. JAL will continue to fly 787s for other international and domestic routes, which are unlikely to be affected by cumulonimbus cloud for the time being, a company spokesman said.

GE and Boeing are working on software modifications to the engine control system, which they will hope will eliminate the problems, a GE spokesman said.

The move followed six incidents from April to November involving five 747-8s and one 787 when aircraft powered by GE's GEnx engines suffered temporary loss of thrust while flying at high altitude.

The problem was caused by a build-up of ice crystals, initially just behind the front fan, which ran through the engine, said a GE spokesman, adding that all of the aircraft landed at their planned destinations safely.

The Dreamliner is made of lighter composite materials, saving on fuel costs for the airlines.