Beijing on Monday lodged strong protest over Tokyo's permission for the separatist World Uygur Congress meeting to be held in Japan, and slammed Uygur separatist Rebiya Kadeer's visit to the Yasukuni Shrine. Analysts warned that Japan's current attitude toward the separatist activities has further damaged its already fragile bilateral ties with China.

The World Uygur Congress, a separatist organization notorious for anti-China activities and closely connected to the other terrorist organizations, held a meeting in Tokyo on Monday.

Kadeer also visited the Yasukuni Shrine, a symbol of Japan's past militarism, which honors 14 major war criminals who led Japan's invasion of China, according to AFP.

Kadeer's visit to Japan came amid the Fifth Trilateral Summit Meeting among China, Japan and ROK that started on Sunday, said Yang Bojiang, a professor of Japan studies at the University of International Relations in Beijing.

"In light of recent fluctuations between both countries, including Tokyo governor Shintaro Ishihara's campaign for purchasing China's Diaoyu Islands, Tokyo granting a visa to Kadeer has more than doubled the complexity of bilateral ties and directly led to tougher deterioration," Yang said.

Premier Wen Jiabao, in his Sunday talk with visiting Japanese Prime Minister Yoshihiko Noda, reiterated China's principles and stances on issues regarding Xinjiang.

"We express our strong dissatisfaction over Japan's permission for the separatist World Uygur Congress meeting and its engagement in anti-China activities in disregard of our firm opposition," Foreign Ministry spokesmen Hong Lei warned on Monday.

Issues regarding Xinjiang are China's internal affairs, and there is no tolerance to interference from outsiders, he said.

China urged Japan to "sincerely respect China's major concern, take measures for damage control and protect the bigger picture of China-Japan ties with tangible moves".

The Yasukuni Shrine is a symbol of Japan's past militarism and its history of invasion of other countries, and the visits in the past by some Japanese political figures outraged the Chinese public and added tensions to ties.

"Only a few members of the Japanese public would visit the shrine, not to mention foreigners," said Yang.

Evidence showed that foreign separatist forces led by the World Uygur Congress masterminded the deadly violence on July 5, 2009, in the Xinjiang Uygur autonomous region, according to the Chinese government. Nearly 200 people were killed.