China lashed a Japanese city's move to commemorate Japan's "stealthy" occupation of the Diaoyu Islands more than a century ago, saying any scheme to infringe upon its territorial sovereignty is nothing but fruitless labor.

Foreign Ministry spokeswoman Jiang Yu made the comments after the city assembly of Ishigaki in Okinawa Prefecture of Japan decided Friday to mark Jan.14 as the day of the Japanese "pioneering" onto the Diaoyu Islands, known as Senkaku in Japan.

"On January 14, 1895, Japan stealthily occupied the Chinese territories of the Diaoyu Islands. The so called 'pioneering' of this nature is absolutely nothing close to a graceful action," Jiang said.

Jiang stressed that China has indisputable sovereignty over the Diaoyu Islands which have been an inherent part of China since the ancient times.

Diaoyu appeared on China's map since the Ming Dynasty (1368-1644). The first record of the islands in Chinese documents can be traced back to the reign of Emperor Yongle (1403-1424) of Ming, more than 400 years before Japan claimed its discovery.

Japan occupied Taiwan and its adjacent isles including Diaoyu three months before it forced the Qing Dynasty (1644-1911) regime to agree, in the Treaty of Shimonoseki signed in April 1895 after China lost a war with Japan, to cede Taiwan and its surrounding islands.

After Japan was defeated in World War II in 1945, all related international documents clearly stated that Taiwan and its surrounding islands were part of Chinese territory. Japan, however, surrendered Diaoyu with the Ryukyu zone to U.S. trusteeship, who in 1971 wrongly returned the islands to Japanese control in 1971 under a bilateral pact.

The U.S.-Japan deal was strongly protested by China, but it agreed when normalizing diplomatic relations with Japan in 1972 to shelve the issue for future solution.

In September, Japan seized a Chinese fishing boat and its crew on waters near the Diaoyu Islands, causing tensions between the two countries. Japan returned the fishermen and trawler only after repeated and strong representations by China.