-Japan confirmed that the Chinese survey ship Xiang Yang Hong 22 set up the buoy in mid-June while monitoring the vessel as it sailed through Japan’s exclusive economic zone (EEZ) in the East China Sea, a government source said. The open-sea area in question is surrounded by Japan’s EEZ.

• Japan has urged China not to undermine Japan’s maritime interests. It’s Chief Cabinet Secretary Yoshimasa Hayashi told a news conference it was “regrettable” that China has set up a small buoy in the waters off Japan’s western main island of Shikoku and north of the southernmost Okinotori Island “without explaining its purpose and other details.”

• Chinese Foreign Ministry spokeswoman Mao Ning said the buoy, which is to monitor tsunami, was set up in the high seas "for the purposes of scientific research and serving public good.

• Last July, China installed another buoy inside Japan’s EEZ near the Tokyo-controlled, Beijing-claimed uninhabited Senkaku Islands in the East China Sea, prompting Japan to lodge a protest and demand its immediate removal.

• Mao said that as the islands, which Beijing calls Diaoyu, are part of China’s territory and its surrounding waters are under the country’s jurisdiction, it is “legitimate and lawful for China to set up hydrological and meteorological data buoys in those areas.”

• China has been intensifying its military activities and maritime assertiveness in the regional waters, with Japan protesting against repeated intrusions by Chinese ships into Japanese waters around the Senkakus.