Japanese Prime Minister Junichiro Koizumi has visited a controversial war shrine in central Tokyo for the fifth time since taking office in 2001.
The Yasukuni war shrine is seen by Japan's neighbors as a symbol of the country's World War II militarism.
Both China and South Korea voiced their irritation over the visit, which they said would further strain relations.
Yasukuni honours Japan's 2.5 million war dead, as well as war criminals convicted by a 1948 war tribunal, reports BBC.
Past visits by Koizumi have contributed to the serious deterioration in Japan's ties with China, South Korea and other victims of Japanese wartime aggression. They protest the visits, saying they pay homage to Japan's wartime, emperor-based ideology.
Osaka High Court in western Japan ruled last month that Koizumi's visits violated the constitution, but the decision lacked the legal force to stop further visits.
But several other rulings have avoided ruling on constitutionality of the visits.
Koizumi defended his visits saying that he was only mourning for the war dead and not supporting the shrine's views that defends Japan's past militarism, informs Guardian.