In a fresh protest against China, Japan has urged Beijing to immediately stop unannounced geographical research it is conducting in Tokyo's exclusive economic zone (EEZ) in the Pacific, a top government spokesman said yesterday.
The Japanese government lodged the protest through diplomatic channels on Tuesday night soon after confirming that a Chinese ship was conducting research off Japan's southernmost island Okinotorishima, Chief Cabinet Secretary Hiroyuki Hosoda said.
The new diplomatic clash comes less than a month after Japan protested a brief incursion by a Chinese submarine into Japanese waters.
The incursion put Japan's navy on alert, though officials in Tokyo said later that Beijing had apologized for the incident.
Hosoda told reporters yesterday that the Chinese ship's activity near the southern island, made without prior notification to Japan, was "extremely regrettable."
There had been no reply from China over Japan's protest as of yesterday morning, he said.
"It is important to abide by the rules, since both sides have agreed not to engage in a sea confrontation, but cooperation," Prime Minister Junichiro Koizumi told reporters Wednesday morning.
Japan and China, East Asia's two most powerful countries, have had persistent tensions. The two are squabbling over interpretations of World War II history, the ownership of East China Sea islands and nearby natural gas fields.
A reconnaissance aircraft belonging to Japan's Maritime Self Defense Forces (MSDF) spotted the Chinese survey ship, the Kexue Yihao, in waters about 320km south of Okinotorishima at around 8pm Tuesday, said MSDF spokesman Taijiro Omata.
That location would be just barely inside Japan's exclusive economic zone.
Chinese vessels are required to notify Japan two months prior to conducting research in the zone, but the ship has not complied and has indicated it plans to stay on, Omata.
Okinotorishima, Japan's southernmost island, is located 1,730km southeast of Tokyo.
The tiny island is comprised of two outcroppings, which have been significantly fortified with concrete against the encroaching waves.
China has argued that the islands are only rocks, and therefore do not qualify as territory that Japan can use to extend its economic zone.
Without the outcroppings, Japan's zone would be reduced by 400,000km2.
Japan disputed China's characterization of the island.
"We don't agree with that opinion," Hosoda said.
Japanese aircraft continued to monitor activity by the 2,579 tonne Kexue Yihao, believed to be conducting maritime research by sending sound waves into the sea, Omata said.
It was the 34th maritime research by Chinese vessels conducted within Japan's 200-nautical mile exclusive economic zone (EEZ) and confirmed by MSDF aircraft this year so far, up sharply from eight cases confirmed the whole of last year, Omata said.
In 21 of the 34 cases, China conducted research within Japan's EEZ without notifying Japan in advance, Hosoda said.