China protest at Japan disputed island visit
3 January 2012 Last updated at 17:21 GMT
China says it has lodged an official protest after several Japanese politicians visited a group of disputed islands in the East China Sea.
Four Japanese citizens, including some local politicians, landed on the uninhabited islands on Tuesday and stayed for two hours, reports say.
The islands - known in Japan as Senkaku and in China as Diaoyu - are controlled by Japan, but claimed by China.
The area has rich fish stocks and possible oil deposits.
Jonathan Josephs reports.