Tens of thousands of people took part in weekend protests against a possible U.S.-led war against Iraq, with many criticizing the government of Prime Minister Junichiro Koizumi for throwing his support behind Washington's threatened use of force.

"Prime Minister Koizumi is supporting a U.S. attack on Iraq. I want to stop the war because Japan would otherwise be a perpetrator," Itsuka Inagaki, a 21-year-old student, said at a rally Saturday in Nagoya.

Inagaki is just one of many increasingly frustrated Japanese who have become vocal in their criticisms of the government for backing Washington's policies toward Iraq.

About 10,000 people rallied in Tokyo on Saturday, according to organizers, later marching through the Ginza shopping district waving banners emblazoned with the phrase "Peace to the World."

Demonstrations organized by numerous citizens' groups were also staged in Osaka and Nagoya as part of an international protest against war.

Similar demonstrations have been held nearly every week in recent months.

In Okinawa, which hosts the bulk of U.S. forces in Japan, organizers said 5,500 people thronged a park in Naha to oppose a U.S.-led war on Iraq.

"It's the soldiers who start a war, but it's humans who have the power to stop unreasonable actions," Tokushin Yamauchi, a former treasurer for the Okinawa Prefectural Government, said at the rally.

In Tokyo, some 200 people attended a meeting at Sophia University to hear journalists warn against the imposition of new controls on the media.

"We have begun hearing words like 'national interest' and 'patriotism,' " Atsushi Okamoto, editor in chief of the monthly magazine Sekai, said. "We are just one step away from hearing people say, 'It's natural that we regulate freedom of speech for the sake of the country.' "