Anti-China protesters gathered Saturday in Tokyo and six other major cities in Japan to rally against what it calls an invasion of disputed islands that both claim are part of their territories.
Protesters held up Japanese flags and chanted, "We will not allow Communist China to invade our territory."
"Senkaku Islands is Japan's traditional territory," Tamogami said. "If we don't protect it, China will make action to take it."
Tamogami called China a "thief" and vowed to protect the islands.
The National Tourism Administration's warning cited an alleged attack against a Chinese tour bus Wednesday by Japanese right-wing activists in the southern city of Fukuoka. The statement, issued late Thursday, didn't give further details of the incident, but warned "Chinese tourists and tour groups currently in Japan or planning to go to Japan in the near future to watch their travel safety."
"I have no intention of accepting [the demand] at all," Japanese Prime Minister Naoto Kan said, according to Japan's official Kyodo news agency.