FACTBOX: Five facts on tensions between China and Japan

(Reuters) - Japan's Prime Minister Yasuo Fukuda and China's President Hu Jintao meet this week as part of a historic May 6-10 visit, the first by a Chinese president to Japan in a decade.

The following are issues and recent strains that could sour the summit of the two Asian giants, whose relations have been rocky due to bitter memories of their wartime past.

* Fukuda voiced concern to visiting Chinese Foreign Minister Yang Jiechi in April about the unrest in Tibet, telling China that it had become an international issue. Japan also ruled out the deployment of Chinese paramilitary guards for the leg of the Beijing Olympic flame's journey through Nagano. Yang has repeatedly said Tibet is a domestic matter, but thanked Fukuda for his support of the Beijing Olympics.

* Frozen dumplings imported from China made several Japanese sick earlier this year. Both Beijing and Tokyo have blamed sabotage rather than production failings for the tainted dumplings.

* A dozen rounds of official-level talks between China and Japan have yet to resolve the long-running dispute over the use of natural resources in the East China Sea. The two countries have been at odds over China's exploration for natural gas in the sea near an area Japan claims as its exclusive economic zone.

The sea also holds a group of eight islets over which both Tokyo and Beijing claim sovereignty.

* Big anti-Japan protests erupted in China in April 2005, when thousands took to the streets to oppose Japan's bid for a permanent seat on the U.N. Security Council and to denounce as 'whitewashing' the accounts in some Japanese government-approved history textbooks.

* Relations were often chilly during former Japanese Prime Minister Junichiro Kozumi's 2001-2006 rule, because of his repeated visits to the Yasukuni Shrine for the war dead, which is seen by many in Asia as a monument to Japan's wartime aggression. Fukuda has vowed not to visit the shrine.

Sources: Reuters

(Writing by Candida Ng, Singapore Editorial Reference Unit)