Small groups of protesters have demonstrated against Japan in several Chinese cities.
They mark the anniversary of the 1931 "Mukden Incident" that led to Japan's occupation of north-east China.
In Beijing, dozens gathered outside the Japanese Embassy, while smaller demonstrations were held in Shanghai, Shenyang and Chongqing.
Anti-Japanese sentiment has been stoked by Japan's arrest of a Chinese fishing boat captain near disputed islands.
The sailor was detained last week after his fishing vessel collided with two Japanese coast guard boats near the islands, called Diaoyu in China and Senkaku in Japan.
Japan has returned the ship and its crew but still holds the captain in detention. China has demanded his release.
Both countries claim ownership of the islands and have argued over the exploration rights for a nearby gas field.
Protesters in Beijing shouted and held signs saying: "Get out of the Diaoyu Islands".
In Shanghai, two men hung a banner saying: "The Diaoyu islands belong to China... return our captain".