TAIYUAN - Chinese archives have made public 36 documents and photos showing that the wartime Japanese state eyed invasion of China long before the World War II.

The archives of Taiyuan, capital of north China's Shanxi Province, made the files public for the first time to commemorate the 69th anniversary of China's anti-Japanese war victory on Wednesday.

The documents include layouts and a topographic map of coal resources in Shanxi.

Among them is a military map showing the roads, mountains, rivers and passes around Gujiao, then a coal-producing town in a suburb of Taiyuan. The map was first drawn in 1919.

Japan invaded northeast China in Sept. 1931. On July 7, 1937, the invading Japanese troops marched to Lugou Bridge in the western suburbs of Beijing, where they clashed with the Chinese army, marking the start of the main phase of the Sino-Japanese War.

"However, the files show that the Japanese imperialists started preparing to invade Shanxi in the early twentieth century," said Cui Junbiao, head of the editing and research center of the archives.

"We can see from here that Japan had been investigating Shanxi's geographic features since at least 1919."

"Their intentions to seize coal were obvious," added Cui.

The documents released feature wartime Japan's plundering of Shanxi's resources and its oppression of Chinese citizens.

They include documents showing cruel treatment of Chinese laborers in coal mines. The Imperial Japanese Army coerced residents to work in mines after the fall of Taiyuan in November 1937.

"We have made them public because we want the Japanese government to face up to its wartime history and to reflect on its crimes," said Cui.