The protest, in Okinawa, was against moves to modify and tone down passages that say the army ordered Okinawans to kill themselves rather than surrender.

Okinawa's governor told crowds they could not ignore army involvement.

Some conservatives in Japan have in recent years questioned accounts of the country's brutal wartime past.

Saturday's rally was the biggest staged on the southern island since it was returned to Japan by the United States in 1972, according to the Kyodo News agency.

Grenades

When US soldiers invaded Okinawa at the end of World War II, more than 200,000 people died.

Hundreds of them were Japanese civilians who killed themselves.

The textbooks, intended for use in high schools next year, currently say that as the Americans prepared to invade, the Japanese army handed out grenades to Okinawa residents and ordered them to kill themselves.

Many survivors insist the military told people to commit suicide, partly due to fears over what they might tell the invaders and because being taken prisoner was considered shameful.

The governor of Okinawa, Hirokazu Nakaima, told crowds the episode should not be forgotten.

"We cannot bury the fact that the Japanese military was involved in the mass suicide, taking into account of the general background and testimonies that hand grenades were delivered," he said.