An All Nippon Airways (ANA) plane made an emergency landing at Tokyo's Haneda airport on Thursday after cabin air pressure dropped, but no one was injured, a transport official said. Flight 584, carrying 265 passengers and crew on a Boeing 767-300, was en route from the southwestern Japanese city of Matsuyama to Tokyo when the pressure dropped temporarily and oxygen masks dropped from overhead compartments. 'The pilot descended the plane to 10,000 feet (3,000 metres) from an altitude of 20,000 feet to cope with the situation,' said the official at the transport ministry's Haneda office. 'No one was hurt although two or three passengers felt sick,' he said. The exact cause of the drop in air pressure was being investigated. 