A powerful conservative group representing families of Japan's war dead has asked Prime Minister Junichiro Koizumi to reconsider his visits to a war shrine that also honors war criminals because of tensions they are causing with other Asian countries, media reports said Saturday.

The Nippon Izokukai, which has long backed visits by Japanese prime ministers to Tokyo's Yasukuni Shrine, cautioned Koizumi about his annual pilgrimages, saying "it is necessary to give consideration to neighboring countries and obtain their understanding," NHK public broadcaster said.

Yasukuni Shrine honors Japan's 2.5 million war dead, including wartime Prime Minister Hideki Tojo and 13 other leaders convicted of the most serious war crimes at a 1946-1948 international war tribunal in Tokyo.

Koizumi's visits there have outraged China and other Asian countries that suffered during Japan's brutal conquest of the region.

The Nippon Izokukai -- a major backer of Koizumi's ruling Liberal Democratic Party -- has maintained a conservative agenda, opposing the construction of an alternative site to Yasukuni to honor the war dead. It has also influenced the portrayal of history in Japanese school textbooks, which critics claim often gloss over Japan's wartime atrocities.

In a statement issued Saturday, the group said the families did not want Koizumi's pilgrimages to turn into a political problem for Japan and urged him to consider the criticisms of China and South Korea ahead of any further visits, Kyodo News said.

The group could not immediately be contacted Saturday.

Koizumi is facing increasing pressure to end his visits, including calls from senior officials in his own party and from a group of former prime ministers.

Japan's relations with China and South Korea have soured in recent months amid renewed criticism that Tokyo refuses to face up to wartime atrocities.

Source: CD/Agencies