At least 651 young people in 30 prefectures were taken to hospitals with convulsions and other maladies Tuesday evening after watching the popular TV cartoon "Pocket Monsters," based on the best-selling Nintendo Game Boy software of the same name, the Fire Defense Agency Agency of the Home Affairs Ministry said Wednesday.

As of 12:30 p.m. Wednesday, 135 of the 651 viewers still required hospitalization.

In Kitakyushu, an 11-year-old girl's condition deteriorated and she was temporarily placed in an intensive care unit. One 5-year-old girl in Osaka and a girl in Funabashi, Chiba Prefecture, were listed in serious condition, officials said.

A doctor at the University of Tokyo Hospital, where four children were admitted after seeing the footage, said viewers seemed to have been affected by strong flashes of light from one scene in the program that stimulated nerve cells and caused the irregular conditions.

The program was broadcast throughout most of the country, airing at 6:30 p.m. Tuesday on TV Tokyo and its 37 network stations. The game and the television program are commonly called "Pokemon" by fans.

TV Tokyo reportedly was flooded by calls from angry viewers Wednesday, and Posts and Telecommunications Ministry officials said they planned to question TV station officials later that afternoon. TV Tokyo launched a task force to determine the cause of the incident. The team includes not only network employees but also outside lawyers and doctors.

Some children treated at hospitals told doctors that they suffered something like whiteouts and that they felt sick after the eyes of "Pikachu," one of the most popular characters on the program, flashed. Pikachu is modeled after a rat.

Other children lost their memory of having viewed the program, doctors said. Those who received treatment range in age from 3 to about 20, officials said. Some of those stricken reportedly came down with their problems while viewing the footage during later TV news reports on the incident.

Of the 651 viewers who were taken to hospitals, 77 were in Kanagawa Prefecture, 76 in Osaka Prefecture, 71 in Tokyo, 70 in Saitama Prefecture and 61 in Aichi Prefecture. Those still hospitalized include 18 people in Aichi Prefecture, 15 each in Osaka and Kanagawa prefectures and 13 in Tokyo.

Hiroshi Uramoto, public relations officer of TV Tokyo, said, "I saw the video of the program. I think the scene that caused the problem is one in which tensions become high and color flashes are emitted for a duration of four or five seconds. "But I believe the same technique was used in the past," he said.

TV Tokyo said the episode was subtitled "Denno Senshi Porigon" ("Computer Warrior Porigon"), and featured characters battling it out inside a computer. The scene that is believed to have caused the problems showed Pikachu creating lightning to counter missiles. The television screen whitened out for one to two seconds when the lightening hit the missiles, viewers said.

The screen emitted intensely bright lights, whose effect viewers described as being as powerful as looking directly into the sun.