BEIJING A trip by Japanese activists to a series of tiny islands at the center of a dispute between Beijing and Tokyo is "illegal" and "troublemaking", the Chinese Foreign Ministry said on Tuesday.
China has lodged a stern protest with Japan, ministry spokeswoman Hua Chunying said at a daily briefing.
The Japanese government purchased the islands, called the Senkaku by Japan and Diaoyu by China, from a private Japanese owner last year, sparking sometimes-violent anti-Japanese protests across China.
The issue has brought Chinese-Japanese relations to their lowest point since normalization of relations between the two countries more than 40 years ago.
(Reporting by Sui-lee Wee; editing by Jonathan Standing)