It was perfectly normal for Chinese ships to conduct research work in the area around the Diaoyu Islands, said Chinese Foreign Ministry spokeswoman Jiang Yu yesterday.

"China, through diplomatic channels, has expressed dissatisfaction over Japan's attitude toward this issue," Jiang told a regular press conference.

The 3,235-ton Dongfanghong No. 2 was reported Sunday morning to be some 30 kilometers west-northwest of Uotsuri, the main isle of the Diaoyu Island group in the East China Sea.

When asked to comment on the issue, Jiang said the Diaoyu and surrounding islands have been Chinese territory since ancient times, and China's sovereignty over them is indisputable.

China could not accept Japanese claims that the Diaoyu Islands are Japanese territory, she noted.

It was China's legitimate right to conduct research work in the waters near the Diaoyu Islands, and no notice of such research work was required, Jiang said.

Officials with the Chinese Foreign Ministry in charge of Asian affairs summoned Japanese diplomats on Monday, and lodged a complaint with them over Japan's approach to the issue.

Jiang also announced that Foreign Minister Li Zhaoxing will pay an official visit to India and Japan from February 11 to 17.

Li will visit at the invitation of Japanese Foreign Minister Aso Taro, spokeswoman Jiang Yu said.

During his stay in India from February 11 to 14, Li will meet with Indian Prime Minister Manmohan Singh and hold talks with Indian foreign minister Pranab Mukherjee, Jiang said.

Li will also attend the opening ceremony of China-India Tourism and Friendship Year.

During Li's stay in India, a meeting will be held for the foreign ministers of China, India and Russia.