TOKYO — Japanese youngsters are getting so addicted to Internet-linking cell phones that the government is starting a program warning parents and schools to limit their use among children.

The government is worried about how elementary and junior high school students are getting sucked into cyberspace crimes, spending long hours exchanging mobile e-mail and suffering other negative effects of cell phone overuse, Masaharu Kuba, a government official overseeing the initiative, said Tuesday.

"Japanese parents are giving cell phones to their children without giving it enough thought," he said. "In Japan, cell phones have become an expensive toy."

The recommendations have been submitted from an education reform panel to Prime Minister Yasuo Fukuda's administration, and were approved this week.

The panel is also asking Japanese makers to develop cell phones with only the talking function, and GPS, or global positioning system, a satellite-navigation feature that can help ensure a child's safety.

About a third of Japanese sixth graders have cell phones, while 60 per cent of ninth graders have them, according to the education ministry.

Most mobile phones in Japan are sophisticated gadgets offering high-speed Internet access called 3G, for "third-generation."

But the panel said better filtering programming is needed for Internet access to protect children.

Some youngsters are spending hours at night on e-mail with their friends. One fad is "the 30 minute rule," in which a child who doesn't respond to e-mail within half an hour gets targeted and picked on by other schoolmates.

Other youngsters have become victims of Internet crimes. In one case, children sent in their own snapshots to a website and then ended up getting threatened for money, Kuba said.

Cell phones tend to be more personal tools than personal computers. Parents find that what their children are doing with them are increasingly difficult to monitor, Kuba said.

Some Japanese children commute long distances by trains and buses to schools and cram-schools and parents rely on cell phones to keep in touch with their children.

Parents typically pay about 4,000 yen (US$39) a month for cell phone fees per child.

Japan boasts a relatively low crime rate compared to other industrialized nations, but some people are concerned that the Internet could be exploited for serious crimes.