Keio Electric Railway Co. trains will begin providing women-only carriages on late night runs in late March following an overwhelmingly positive response to a trial service in December, company officials said Thursday.

The private railway operator said the last car on eight express trains leaving Shinjuku Station after 11 p.m. will be limited to female passengers beginning March 27. The move is in response to the increasing frequency of sexual harassment against female passengers.

While there have been several cases of carriages being designated specifically for women and children in Japan, providing women-only cars on this scale is unprecedented.

The officials said the service will be introduced together with a major timetable change the same day.

Women-only carriages will be identified by 40 cm x 30 cm stickers in Japanese and English on windows, internal and external doors. Station staff will shepherd passengers on platforms at Shinjuku, Sasazuka, and Meidaimae stations.

Conductors will be assigned to some of the cars during the introduction period to enforce the policy.

Boys under junior high school age accompanying female passengers will be able to use the carriages, as will disabled people or their attendants if one of them is female.

The railway ran the service on a trial basis in December and conducted a survey of 300 passengers.

Of the 199 respondents, 69 percent supported the idea, with 82 percent of female respondents expressing support.

The Tokyo Metropolitan Police Department said there were 1,854 arrests in 2000 in connection with sexual harassment on Tokyo trains, up from 1,555 the previous year.

Keio said the various awareness campaigns it has conducted over the past couple of years targeting sexual harassment on trains have not been effective enough.

Segregated cars were also welcomed by male passengers in the wake of a series of high-profile cases of wrongful accusation. Fear of being falsely accused has created a phenomena called "banzai commuting," in which high-strung male passengers leave their arms in the air to avoid suspicion.

"I welcome it," Megumi Sugino, 36, from Setagaya Ward said when asked about the news at Shinjuku Station, adding she would like to use it even if it means she has to walk a longer distance on the platform.

"I just hate having my body touching others. I have been groped before."

But the voices of cynicism are being heard, including that of a 54-year-old man who gave only his last name, Atsumi. He said the initiative will have no practical effect and is simply an attempt to win the hearts of passengers.

"There are no men's only cars, it is reverse discrimination," Atsumi said. "I don't think it will spread to other railways."

Keio said it has no plans to expand the service to other times of the day, despite the frequency of sexual harassment during morning rush hour. The company said it is not feasible to introduce the service when trains arrive every two minutes and platforms are filled to capacity.

Other Tokyo railway operators received the news with curiosity but said they have no plans to follow suit.

A Seibu Railway Co. official said the company is not considering such a move, saying, "There has not been a consensus yet about the wisdom of such a system."

Neither is Odakyu Electric Railway Co. planning to follow Keio. An official explained that trains running on some of its lines are detached where lines divide, making it impossible to secure one carriage for women only. He also pointed to the cost of hiring staff to enforce the system.

While welcoming Keio's move, Eiko Ishibashi, a member of a civic group calling for a better commuting environment, said sexual harassment is a side effect of the root issue of overcrowding.

"Efficient transportation has been the top priority for Japanese railways and passengers' rights, including protecting their private area, have been ignored," she said. "It is high time for a paradigm shift and for railways to provide comfort for commuters."