Following a recent spate of attacks on Web sites operated by its agencies and departments, the Japanese Government said it would wage war on hackers.

The hard line statement appeared to bring even more hackers out to test the security of government sites, with the site of Japan_s ministry of posts and telecommunications in Okinawa defaced, as well as the site of Japanese Institute for Dissemination and Research of Government Data altered, among others. Starting with the Science and Technology Agency, hackers quickly rolled through government sites. In most cases, messages were added in Chinese or English condemning Japan for the 1937 massacre of civilians in Nanjing, then called Nanking, in southern China. The day before the hacking began, a forum was held in Osaka denying that invading Japanese soldiers killed as many as 300,000 Chinese after the city fell. The Chinese government protested the meeting. One of the altered Websites said the Japanese are a people who do not have the courage to face the truth of history. In other attacks, data including the national census were erased from the Management and Coordination Agency_s statistics bureau and 3,500 files were deleted from a home page of the National Personnel Authority. Retrieval efforts have begun. In addition, thousands of hacking attempts were confirmed in the past week on sites operated by the Defense Agency, Supreme Court, Bank o Japan, Finance Ministry, Foreign Ministry and others. Japan is the only major industrialized country that does not penalize unauthorized entry into computer networks. That will change next week, when a law takes effect punishing unauthorized access with up to a year in prison or a $470,000 fine.