Japan has summoned a Chinese diplomat in Tokyo to submit the latest tit-for-tat protest over islets claimed by both Asian powers. Japan says four Chinese ships spent a day inside disputed island waters.
Japan's government said it had protested "strongly" on Thursday by summoning a Chinese envoy in Tokyo over a trip by four Chinese ships to waters near uninhabited islands controlled by Japan in the East China Sea.
Japanese chief cabinet secretary Yoshihide Suga told a press conference that China had conducted an "intrusion" that had been "totally unacceptable."
China's foreign ministry did not immediately respond to the latest Japanese missive.
Japanese Foreign Minister Fumio Kishida said Tokyo had "pressed for an immediate exit of all the ships."
Japan's coastguard said the Chinese ships left island waters at Thursday noon, local time, after a 28-hour stay.
Three-way maritime dispute
Japan purchased the Senkaku Islands, which are called Diaoyu by China, from a private Japanese owner last September. Taiwan also claims the island group, which it calls Taioyutai.
For months, aircraft and ships from each country have staged cat-and-mouse maneuvers near the island group, which is located in rich fishing waters. Vast natural resources are thought to lie below the local seabed.
China's state news agency Xinhua had on Wednesday accused Japan of renouncing its pacifist stance imposed after World War Two by the United States and its allies.
This followed Japan's unveiling of a giant helicopter carrier ship called Izumo, worth $1.2 billion (902 million euros). Last year, China commissioned its first aircraft carrier, Liaoning.
The island wrangle coincided on Thursday with the publication of a survey showing that Chinese and Japanese people hold the least favorable views of each others' countries for almost a decade.
A total of 92.8 percent of Japanese people had a bad or relatively bad impression of China, while 90.1 percent of Chinese had similar feelings towards Japan, according to the poll by the state-run China Daily and Japanese thinktank Genron NPO.
It was the ninth time the annual survey has been carried out, and the China Daily said the results were "the worst in almost a decade".
The two countries' relationship remains soured by Japan's brutal occupation of China before and during World War Two.
Beijing regularly accuses Tokyo of failing to atone for its imperialist past, while Japan says its neighbours use history as a diplomatic stick to beat it with.
ipj/msh (Reuters, AFP,dpa)