A plane with hundreds of passengers made an emergency landing in Tokyo after 12 people were hurt during mid-air turbulence.

The American Airlines flight AA280 from Seoul to Dallas was diverted to Japan's Narita airport following the incident.

Kyodo News agency said the plane was carrying 240 passengers and 15 crew and encountered severe turbulence while flying through a rapidly intensifying winter storm.

Twitter user Erin Cherry wrote: "Landed in Tokyo after massive, massive turbulence on #aa280. Broken glass etc flying inside cabin. Some were injured."

"American's primary concern at this time is for our passengers and crew on board the airplane and our team in Narita is providing assistance. We will provide additional information as it becomes available," said the airline in a statement released after the incident.

A powerful winter storm is developing over Japan, some 35,000 feet above sea level. It is expected to become a meteorological "bomb" as its central pressure plummets to 948 millibars near Hokkaido, Japan's northernmost major island, by Wednesday morning local time.