But the High Court in Nagoya also refused Thursday to halt the Air Self-Defense Force mission, the Kyodo News Service reported.

Japanese planes provide ferry service between Kuwait and Baghdad, and the government argues that the Baghdad airport is not a war zone.

The suit was brought by a group of 1,100 Japanese anti-war activists who want a complete halt to support for the coalition in Iraq. Japan has already withdrawn ground soldiers who had a rebuilding mission in Iraq.

The constitution adopted after World War II bans the Japanese military from using force outside the country. The court ruled that the Kuwait-to-Baghdad airlift supports the use of force by other countries and is thus unconstitutional.

Both sides claimed victory and are not expected to appeal.