Tokyo summoned China’s envoy on Tuesday in protest after what it says was another incursion into its territorial waters around islands at the centre of a bitter dispute with Beijing.
The move comes after Chinese state vessels spent much of Monday in waters around the islands and as the two sides show no sign of backing down in a dispute that has badly affected trade between Asia’s two largest economies.
Two maritime surveillance boats arrived in the area shortly before 9.30am, the Japanese coastguard said, with Kyodo News reporting they had remained there for around 14 hours.
Chief Cabinet Secretary Yoshihide Suga told a news conference the actions were “absolutely unacceptable”, adding Ambassador Cheng Yonghua had been called to the foreign ministry to hear Japan’s “strong protest”.
Chinese ships have repeatedly ventured into the waters, in what observers say is Beijing’s bid to create a “new normal” in which Tokyo does not have effective control over the archipelago.
A Chinese government plane entered the chain’s airspace in December, setting off sorties by Japanese fighter jets.