An anti-Japanese petition signed by a million Chinese has come as an embarrassment to the governments of both countries
Chinese activists handed in the protest letter at the Japanese embassy in Beijing on Thursday, to mark the 72nd anniversary of the start of Japan's occupation of northeast China.
Launched by seven Chinese Web sites and signed by 1.12 million people within a month, the petition demanded that Japan apologise for and compensate Chinese victims poisoned by abandoned chemical weapons from World War II.
But there was no mention of it in the official Chinese media and the Japanese Foreign Ministry in Tokyo denied all knowledge of it.
Japan's wartime record is a regular source of tension between the two countries.
In the most recent case, a man died and more than 40
people were injured last month when five metal barrels containing mustard gas were unearthed in the Chinese city of Qiqihar.
Japan has apologised for the incident, but refused
calls for compensation on the grounds
that the issue was settled when
the two countries established diplomatic ties in 1972.
"Ordinary people in China have had anti-Japanese feelings for a long time, so news of this online petition does not surprise me", Wu Jiaxiang, a former aide to the Communist Party leadership, told BBC News Online.
"But the government is trying to play it down. Japan is a big overseas market for China and an important provider of investment and technology," he said.
China is usually keen to commemorate sensitive events such as the "Mukden Incident" in the hope of gaining further diplomatic leverage.
1931 MUKDEN INCIDENT
Japanese army officers staged an attack on its railway in north east China
Used incident to justify seizure of nearby town of Mukden (Shenyang)
Japan went on to occupy all of north east China
Incident now seen as a cause of WWII in Pacific
Thursday's anniversary, however, was marked with little fanfare and the authorities rejected an application by 50 activists to stage a protest march in Beijing.
China's communist party has always been wary of spontaneous protest - whether online or on the street.
But the younger generation of leaders who have taken power in Beijing in the past year also have their own reasons for trying to dampen down enthusiasm for the anti-Japanese petition.
History no barrier
The new government is showing signs of wanting to mend fences with Japan and tone down China's traditionally harsh public rhetoric.
Foreign Minister Li Zhaoxing said on a visit to Japan last month that history should not be a "burden" but rather a "source of wisdom and strength" .
This appears to suggest he thinks the war should no longer be a barrier to better ties.
But not everyone in the new leadership agrees, according to Phil Deans, Director of the Contemporary China Institute at SOAS London University.
"The more progressive reformers see Japan as a strategic economic partner and want to improve relations as part of the overall Chinese policy of reform and opening up.
"But more conservative groups in the leadership often use the historical issue of Japan as a means of slowing down or provoking opposition to the economic changes," Dr Deans told BBC News Online.
"You are not allowed to stand up and say 'reform is terrible' but if you say 'Japan is terrible' no one can argue with you ... because to be positive about Japan is to be considered un-Chinese."
Dr Deans believes an anti-Japanese sentiment is "fundamental to contemporary Chinese nationalism"
Jia Qingguo, professor of international relations at Beijing University, agrees that the Chinese government has to tread a fine line in its dealings with Japan.
But in his view it is Japanese leaders who are slowing progress in the relationship by continuing to provoke China on sensitive issues such as visiting war shrines.
"China has made sincere efforts in recent months to improve relations but these have not been reciprocated by Japan", said professor Jia.
He said the Chinese government "understands" the desire of its individual citizens for compensation on the weapons issue, but does not want to "interfere"
But another analyst in Beijing, Liu Junning, thinks the difference between official and unofficial attitudes suggests ordinary people want to have a bigger voice in China's foreign policy.
"It's an important development since the authorities have always insisted they have the exclusive right to deal with foreign affairs. The people are very much discouraged from expressing their opinions on such matters.
"So it seems to me, the petition is something of significance between the Chinese government and its people rather than between China and Japan," he said.