BEIJING - The landing on China's Diaoyu Islands by a pack of Japanese rightists on Sunday was the latest of a series of provocations that flagrantly infringed Chinese sovereignty.

The move, under the so-called excuse of "mourning war dead in World War II," blatantly harmed the long-standing and hard-won China-Japanese ties and hijacked the public opinion in Japan.

It is illegal for them to step onto the Chinese islands without approval. It actually was even not approved by the Japanese government.

Recently, Japanese rightists have repeatedly tested China's patience by supporting a high-profile landing on the Diaoyu Islands in July by two right-wing politicians from Ishigaki, Okinawa, and later by staging the "islands-purchasing" farce.

There is ample historical evidence to show that the Diaoyu Islands have been Chinese territory since the Ming Dynasty (1368-1644). The fact is recorded in many historical documents. Even a map published by Japan between 1783 and 1785, which marked the boundary of the Ryukyu Kingdom, labelled the Diaoyu Islands as Chinese territory.

The islands were unfortunately seized by Japan during the 1894-1895 Sino-Japanese war and had since been under its occupation until its defeat at the end of World War II.

However, they were not returned to China, its rightful owner, and were wrongly assigned to the then US-controlled Ryukyu zone under an illegal treaty signed between Tokyo and Washington in 1951, which has never been recognized by the Chinese government.

Sunday's landing, along with a barrage of other provocations, has poisoned the atmosphere of the Sino-Japanese relations and constituted another setback for both countries' efforts to further their political and economic ties.

The Japanese rightists should immediately stop any action that undermines Chinese territorial sovereignty and be barred from fuelling the tension between the two neighbors.

To this end, the Japanese government should act with great responsibility and proceed from the overall interests of the Sino-Japanese relations to seek a peaceful settlement of any disputes.