Defenders of Japan's postwar Constitution in its present form and others advocating its amendment held rallies across the country May 3, a national holiday commemorating the 62nd anniversary of its enforcement.

Nobel Prize-winning physicist Toshihide Masukawa speaks at a rally to defend the Constitution on May 3 in Tokyo. KYODO PHOTO

At a rally in Hibiya Park in central Tokyo attended by around 4,200 people, Nobel Prize-winning physicist Toshihide Masukawa warned of the forces driving to change the war-renouncing supreme law.

Japan "has gone as far as to send Self-Defense Forces vessels to waters off Somalia on the basis of a constitutional interpretation," he said, referring to the SDF's antipiracy operations off the Horn of Africa being conducted in the name of a policing action.

"(Those calling for constitutional revision) are longing for the right of belligerency," which the Constitution denies the country under Article 9, the Kyoto Sangyo University professor emeritus said.

Meanwhile, Diet members and others advocating revisions to the Constitution held a gathering in Shinjuku Ward, Tokyo, attended by around 500 people.

"Constitutional revisions are indispensable to building international peace in the true sense of the words. The time has already ripened," said Yuriko Koike, a lawmaker of the ruling Liberal Democratic Party and a former defense minister.

Koike went on to criticize the main opposition Democratic Party of Japan, whose members are often divided over issues related to the peace provisions of the Constitution, saying the party would not be qualified to assume power as long as it avoids mapping out its stance on the subject.