TOKYO (AP) _ Japan has bolstered the defense of its computer systems in the face of a surge in cyberattacks believed linked to anti-Japanese sentiment in Asia, increasing staff and creating a new agency to coordinate its efforts.
Government officials are reluctant to publicly pin the attacks on Chinese and South Korea hackers because of the difficulty of identifying their source, but a surge in attacks coincided with violent anti-Japanese protests last month in China.
``I can't comment on media reports that many of these attacks came from China and South Korea,'' said Naoki Miyagi, another center official. ``But it's true that there were provocative messages on Chinese Web sites calling for cyberattacks on Japanese establishments.''
There was no indication that any of the attacks were backed by the Chinese or Korean governments and they appeared to be the work of individuals or groups acting on their own.
Cyberattacks have recently hit Japan's National Police Agency, its Self-Defense Forces and the Defense and Foreign ministries, as well as other sites, such as businesses and a Tokyo war shrine criticized in Asia for honoring convicted war criminals, officials say.
No government site has been crippled by the attacks, but Miyagi said the assaults can clog and slow down computer connections. There have been no successful attempts to change the information posted on those sites, he said.
Some of the attacks, however, have been intense. An official at Tokyo's Yasukuni Shrine, which honors war criminals among Japan's 2.5 million war dead, said on condition of anonymity that the site there had been hit with 15,000 bogus visits per second, preventing access by legitimate users.
The demonstrations in China were triggered by Tokyo's approval of a history book that detractors say whitewashes atrocities committed by Japan during its conquest of East Asia in the 1930s and 1940s.
To handle the explosion in Internet attacks, Japan established a National Information Security Center on April 25 and anti-cyber attack staff was increased from 18 to 26.
``This reform is in part the government's response to the recent surge in cyberattacks,'' Yoshitaka Nishiura, a center official, said Wednesday. ``But more than that, we decided we needed a department that oversees information security for the government as a whole.''
Experts say the recent flood of Internet intrusions marks a shift from occasional ``kid's play'' hacking to organized, full-scale, politically motivated assaults.
``People have discovered that they can conduct 'digital demonstrations' at any time,'' said Itsuro Nishimoto, of SecureNet Service, a division of Internet security company LAC.
``It's almost unthinkable that a huge flock of Chinese people could come to Japan and hold a protest,'' he said. ``But digitally, it's possible.''
The Internet attacks appear to be part of a broader use of advanced technology in the anti-Japan protests.
Demonstrators said word of protests in China spread through e-mail and mobile phone text messages, and details were also posted on popular Internet sites.
Authorities used the same method to warn people against demonstrating in the days after the riots.
Last week, Beijing police sent this text message to millions of cell phone users in the capital: ``Express patriotism rationally. Don't take part in illegal protests. Don't make trouble.''
Authorities also shut down activists' Web sites.