The palace said Wednesday that the ailing Emperor Hirohito's condition was improving, but Cabinet ministers stayed near telephones for fear of the worst, and members of the imperial family canceled scheduled activities.

The frail 87-year-old, who began vomiting blood Monday and has since had three transfusions, was in serious but stable condition and under constant medical surveillance, palace and news reports said.Chief physician Akira Takagi told a news conference Hirohito showed symptoms of jaundice and anemia but was alert. The physician refused to say if the internal bleeding plaguing the emperor had ceased.

Reports said the bleeding came from the area in his duodenum where doctors performed an intestinal bypass around an enlarged pancreas a year ago.

Takenori Sugawara, a spokesman for the Imperial Household Agency, said that Hirohito was receiving intravenous fluids but appeared "headed in a favorable direction."

A chapter in Japan's modern history will close with the passing of Hirohito, the world's oldest and longest-reigning monarch. The Japanese media monitored the emperor's condition around-the-clock.

Crown Prince Akihito, 54, and Princess Michiko visited the emperor Wednesday in their fourth visit since he fell ill.

The emperor's illness prompted Foreign Minister Sosuke Uno to cancel his plan to leave Thursday for talks in Washington with U.S. Secretary of State George P. Shultz.

Doctors began administering emergency care after the emperor vomited blood repeatedly from Monday night through Tuesday morning, the imperial agency said.

The nationally circulated daily Yomiuri Shimbun, quoting palace medical sources, said doctors acted after Hirohito initially vomited about a pint of blood. Court physicians suspected an enlarged pancreas was causing hemorrhaging of the emperor's duodenum, part of the small intestine, according to the sources.

In September, doctors performed an intestinal bypass operation in the same area, circumventing a blockage caused by the enlarged pancreas.

Major Japanese dailies carried front-page headlines Wednesday reporting that the emperor remained in serious condition, while about 100 reporters maintained close watch over the Imperial Palace, a green oasis in the center of Tokyo.