BEIJING, Sept. 16  -- Chinese archivists on Tuesday showed how China successfully used guerrilla warfare to defend a key base against Japanese invaders in the eastern Jiangsu Province in 1941.

The State Archives Administration's release of documents on the defense of Yancheng City came as China continues to mark the 69th anniversary of victory over Japan. This batch is the 23rd in a series of wartime documents released daily by the administration since Aug. 25.

On July 20, 1941, 17,000 Japanese troops and members of their puppet forces began a massive offensive against Yancheng, attempting to destroy the main force of the Chinese New Fourth Army.

The Chinese side repelled the Japanese largely through ambush attacks. They also used naval mines to sink several enemy warships.

In early August, the New Fourth Army launched operations to recover surrounding towns captured by the Japanese, forcing the invaders to retreat.

During the battle that lasted for more than a month, the Chinese army mustered over 130 attacks, killing 3,800 enemies and suffering more than 1,000 casualties of their own.