China has defended a survey ship's entry into disputed waters near Japan, saying the ship was carrying out a normal maritime survey. China also accuses Japan of sensationalizing the incident, as Daniel Schearf reports from Beijing.
China rejected Japan's concerns about a Chinese ship entering disputed waters in the East China Sea.
Tokyo had demanded an explanation and an apology from Beijing. Tokyo said the ship entered an area near a disputed island chain on Sunday and then proceeded into a part of Japan's exclusive economic zone.
China's Foreign Ministry spokeswoman Jiang Yu would not confirm if the ship entered Japanese waters. But she said the island chain, called Senkaku in Japan and Diaoyu in China, has been a part of China since ancient times.
"China's ships are having normal maritime scientific investigation and survey in the seas adjacent to the Diaoyu Islands. It is China's just and sovereign right," she said.
Jiang said China had expressed "dissatisfaction" with the Japanese authorities and their attempts to "sensationalize" the incident.
The disputed islands are of special concern to Chinese nationalists who link Japan's control of them to China's past humiliations by foreign powers.
Japan seized the islands and the surrounding fishing grounds in 1895 when it colonized Taiwan.
The islands also have an economic significance. A U.N. report in 1969 said large oil reserves were suspected in nearby waters, prompting both Beijing and Taipei to lay claim to the islands.
Hong Kong's Ta Kung Pao newspaper reported last week that China had started pumping gas from another disputed area in the East China Sea at the Chunxiao oil field. But Jiang said the report "did not comply with facts."
Japan and China have experienced a warming of relations since Japan's Prime Minister Shinzo Abe visited Beijing last October.
But the maritime dispute could cast a cloud over an upcoming visit to Japan by China's Premier Wen Jiabao in April, when the two sides are to mark 35 years of diplomatic relations.