BEIJING, Sept. 14 (Xinhua) -- China on Sunday released documents on a major battle against the Japanese army in central China's Hubei Province in 1940 as the country marks the 69th anniversary of the victory against Japanese aggressors.

This is the 21st part in a series of documents released daily by the State Archives Administration starting Aug. 25.

On May 1, 1940, 200,000 Japanese troops began a drive toward the Zaoyang and Yichang areas of Hubei, attempting to destroy the main force of the Chinese army's 5th War Zone and assault the war-time capital, Chongqing.

The Chinese side assembled six groups with a total of 380,000 troops to repel the Japanese. They fought until June 18.

The Chinese troops suffered serious casualties due to lack of heavy weapons, poor coordination and wrong judgements about the Japanese army's strategic intentions.

General Zhang Zizhong, commander in chief of the 33rd Army Group, was killed during the battle on May 16.

He was the highest-ranked officer killed during the war against Japanese aggression. There are roads named after him in Beijing, Shanghai and Tianjin.

China has officially designated Sept. 3 as Victory Day to mark Japan's surrender on Sept. 2, 1945.