Overseas Chinese in the U.S. city of Houston on Tuesday presented a written protest over the Diaoyu Islands to the Japanese Consulate General in the city, condemning the Japanese government's provocations over the islands.

The Japanese government last week formally signed a contract to "purchase" part of China's Diaoyu Islands, triggering widespread anti-Japanese protests in China and abroad.

About 500 overseas Chinese rallied in front of the Japanese Consulate General in Houston downtown, joining their compatriots across China in marking the 81st anniversary of the "Sept.18" incident, which marked the beginning of the Japanese occupation of Northeast China.

They recalled bitter memories of Japan's invasion of China decades ago and condemning the country's recent provocative move over the Diaoyu Islands and demanding Tokyo stop further provocation and territorial intrusion.

The protestors marched around the Japanese Consulate General building, singing songs composed during the China-Japan war and shouting slogans like "Diaoyu Islands Belong to China", "Remember Pearl Harbor, Stop Japanese Aggression."

An airplane circled above downtown Houston with a banner reading "Japanese Adventurism = US Trouble".

The protest letter, presented by the Houston Diaoyu Islands Coalition to the Japanese Consulate General, was read at the gathering.

"We wish to remind the Japanese government that it was declared in the Cairo Communique of December 1, 1943, that 'Japan shall be stripped off all islands in the Pacific which she has seized or occupied since the beginning of the First World War in 1914, and that all territories Japan has stolen from the Chinese shall be restored to China," the letter said.

The letter pointed out that "numerous documents, dated as early as 1403, recorded the Diaoyu Islands as part of China."

"On the eve of the 67th anniversary of the unconditional surrender of Japan at the end of World War II, the Japanese actions regarding the Diaoyu Islands fully expose Japan's aggressive ambitions and expansionist agenda and, once again, it reminds the world of Japan's militarism and imperialistic expansion that led to its invasion of Asia and the attack on Pearl Harbor in 1941," the letter said.

"We strongly protest against these provocations by Japanese right wing politicians. Japan's occupation of the Chinese Diaoyu Islands lack all legal basis," it said.

"Through today's demonstration, we want the world to know that the Diaoyu Islands are China's territory, "said William Q Hua, president of China Peaceful Development Alliance-Houston. "We also want the world to know that Japan's militarism and expansionism should not be given any chance to have their way."

"To many in East Asia and the Asian community here, Japan's decision to upgrade its control over the Diaoyu Islands, an integral part of China, its failure to repent, and its refusal to compensate the victims of Japanese assault, indicates that Tokyo has failed miserably to live up to the expectation of the international community," said Peter Li, Associate Professor of East Asian Politics Social Sciences Department at University of Houston.

"The United States has an unshakable responsibility for peace and stability of East Asia," Li said. "Supporting Japan's illegal claim to the Diaoyu Islands serves no American interests. Providing security assurance to Japan over the Diaoyu Islands could drag the United States into an armed conflict involving the three top economic powers of the world," he said.

The United States needs to "stand on the right side of history," Li said.

Last Saturday, an activity was launched to collect signatures for a petition to be submitted to the U.S. government and Congress on Oct. 6 over the issue of the Diaoyu Islands, according to Steven Pei, chairman of the Houston Diaoyu Islands Coalition.

The petition asks the United States to take a neutral stance over the Diaoyu Islands issue, both from the perspective of the U.S.-China relations and for the interests of the U.S. government and its people, said Pei.

The signature-collecting activity, initiated by the Houston Diaoyu Islands Coalition and jointly launched in five U.S. cities, aims to get at least 10,000 signatures from supporters of China's sovereignty over the Diaoyu Islands, said Pei.

On Sept.18, 1931, Japanese troops raided a railway station in China's Shenyang and then accused the Chinese army of being behind it. The event eventually led to the Japanese occupation of Northeast China.