A Tokyo subway operator and six major private railway firms plan to launch a joint campaign today to stress their ban on mobile-phone use in trains during rush hour, due to the danger of interference with pacemakers, the companies announced Sunday.

Teito Rapid Transit Authority, Tokyu Corp., Kinki Nippon Railway Co., Keihan Electric Railway Co., Hankyu Corp., Hanshin Electric Railway Co. and Nankai Electric Railway Co. will urge passengers via intercom announcements to turn off their phones.

The message will be more assertive in tone from the current announcement, which merely asks passengers to please refrain from using mobile phones.

All the firms except Tokyu plan to impose the restriction on all trains during the morning and evening rush hour periods. Tokyu will ban the phones only in even-numbered train cars, but this ban will apply at all times.

From August, Keio Teito Electric Railway Co. changed its restriction to apply only to areas around seats reserved for elderly or handicapped persons.

Both Tokyu and Keio concluded it would be more effective to limit restricted areas, officials with both companies said.

Japan Railway groups and many other private rail firms have already been asking passengers to refrain from using mobile phones on trains due to possible electromagnetic interference with medical devices.

An official of the Japan Nongovernment Railways Association, which comprises 72 private railway companies, said, "Though we have taken different approaches, passengers should basically mind their manners."

A member of a civic group supporting pacemaker users said, "Pacemakers are becoming more widely understood in society, and we are happy about the railway companies' decision, although we have not received any reports of pacemakers malfunctioning in trains due to cellular phones."