Japan plans to launch satellites to monitor the world's oceans, a report said yesterday, as Chinese government ships sailed in waters around islands controlled by Tokyo and claimed by Beijing.
Nine satellites were planned for launch in the next five years to counter piracy and monitor the movements of foreign ships intruding into Japanese territorial waters, business daily Nikkei reported. They will also collect data for forecasting natural disasters such as tsunamis, it said.
The report, which cabinet officials could not immediately confirm, came as Japan's coastguard said three Chinese government ships entered waters around the Senkaku islands in the East China Sea, which China calls the Diaoyus.
The maritime surveillance vessels entered the 12-nautical-mile zone around Uotsurijima, one of the islands, at about 9.30am, the coastguard said. The ships left shortly before 1pm.
Ships from the two countries have for months traded warnings over intrusions into what each regard as their territory, as Beijing and Tokyo jostle over ownership of the islands. The four-decade territorial row reignited last September when Japan nationalised three islands in the chain, in what it said was a mere administrative change of ownership.
Last Wednesday, Japan said it had voiced "serious concern" to China at the construction of a drilling rig near a disputed and potentially rich gas field in the East China Sea.
A Chinese vessel has been seen building what appears to be a drilling platform 26 kilometres on the Chinese side of the median line between the two nations, Chief Cabinet Secretary Yoshihiko Suga said. Japan considers the median line to be the appropriate divide, while China does not.