"We have made decisions based on a comprehensive assessment of the security situation in the country or region, as well as its political and social conditions," said Minoru Kihara, a spokesman for the Japanese government, according to the news agency.
The Japanese Embassy in China urges its citizens in the country to be aware of their surroundings.
"If you see a person or group that looks the least bit suspicious, do not approach them and leave the area immediately," the warning reads.
As recently as Saturday, China advised its citizens against traveling to Japan after the latter expressed support for Taiwan. Japanese Prime Minister Sanae Takaichi said earlier in November that Japanese forces could be deployed if China attacks Taiwan.
The government in Beijing considers Taiwan to be part of China, but in practice Taiwan has been self-governing and separate since the end of the Chinese Civil War in 1949, when rival governments took over in Beijing and Taipei respectively.
