BEIJING - A group of flag-waving Japanese activists set foot on turf claimed by both Beijing and Tokyo yesterday, in a tit-for-tat move just four days after Chinese nationalists did the same.
The landing on the islands - called Diaoyu by the Chinese, but called Senkaku and controlled by the Japanese - immediately drew public protests, as well as official condemnation from the Chinese.
A flotilla of ships carrying about 150 activists from Japan had set sail for the islands on Saturday, with 10 men from the group going ashore yesterday morning.
They waved flags and sang the Japanese national anthem, before leaving two hours later.
The provocative act led to thousands of people in China - from Guangzhou city in the south, to Chengdu in the west - taking to the streets later to voice their unhappiness.
In the southern city of Shenzhen, protesters smashed the windows of ramen restaurants and threw bottles at Japanese cars.
A spokesman from China's Ministry of Foreign Affairs said it had lodged strong protests with Tokyo over the landing, noting that it violated China's territorial sovereignty.
"The Japanese side should handle the current problem realistically, to avoid seriously disrupting overall Sino-Japanese ties," said spokesman Qin Gang.
The latest upturn in tension over the disputed isles in the East China Sea and near the Shirakaba or Chunxiao gas field comes after a Chinese group led by activists from Hong Kong successfully went ashore on Wednesday.
The 14 men were detained and then released by the Japanese after two days.
Tokyo's handling of the incident was markedly more restrained than when it tried to prosecute a Chinese captain whose trawler collided with a Japanese patrol boat near the islands in 2010.
That incident sparked a spat which saw Beijing limit exports of rare earths to Japan.
But the Japanese government has faced criticism that it is too soft, which has led Japanese right-wing activists to take matters into their own hands.
Their landing, however, is illegal, as Tokyo bars anyone from the islands who does not have prior permission.
Yesterday, some participants at a forum regarding the islands hosted by China's Global Times newspaper urged Beijing to take stronger action to prevent a repeat of the Japanese landing.
"We must adopt stronger retaliatory action so that they will back down after realising the difficulties," said the hawkish Major-General Luo Yuan of the People's Liberation Army, without specifying what sanctions should be taken.
He also suggested naming China's first aircraft carrier after the Diaoyu Islands to emphasise China's sovereignty over them, as well as holding military exercises in the waters near them.
While noting that Japan holds the upper hand, enjoying control over the islands since 1972 when the United States gave them up, some say the tide is slowly turning in China's favour.
They see the Chinese landing as a small win: it marks the first successful landing by Chinese activists since 2004, it had the support of volunteers from Hong Kong, Macau and the mainland, and it did not meet with much resistance from the Japanese government.
"This has to do with China's economic strength, as well as the unity of the Chinese people," said Taiwanese Chris Chen, author of a book on overseas Chinese.
The island is also claimed by the Taiwan government, which also registered protests yesterday with Japan.