An American Airlines plane flying to the U.S. had to make an emergency landing in Tokyo after hitting severe turbulence.<br/> <br />Several people were injured.<br/> <br />Passengers said the plane dropped suddenly and rocked for half a minute.<br/> <br />(SOUNDBITE) (English) UNIDENTIFIED PASSENGER, SAYING:<br/> <br />"Some people were walking around and might have hit their heads because it was a pretty big drop."<br/> <br />The turbulence was caused by a winter storm in northern Japan that's brought heavy snow and winds gusting at typhoon speeds.<br/> <br />Japanese media say more than 300 flights have been cancelled across the country.
