Nationalists raised Japanese flags on an island at the heart of a corrosive territorial row yesterday, sparking street protests in China and an angry reaction from Beijing.

Around a dozen members of the right-wing group Gambare Nippon (Hang In There Japan) swam ashore, an AFP journalist witnessed, from a 20-boat flotilla carrying activists and lawmakers.

The landing came just days after Tokyo deported pro-Beijing protesters who had landed on the island, part of a chain administered by Japan but claimed by China, which said yesterday’s action was illegal.

Local Tokyo politician Eiji Kosaka, one of the men who made it to the island in the East China Sea, said the group had planted Japanese flags on a hillside and on the shore.

“This is undoubtedly Japanese territory,” he told reporters aboard the flotilla on his return.

“On the mountain we found (the ruins of) Japanese-style houses that had places for drying fish.

“It is very sad that the Japanese government is doing nothing with these islands,” he said, adding the nationalists’ expedition had been “a great success”.

The 150 people who had made the voyage, including eight parliamentarians, sailed back to far southwestern Ishigaki yesterday.

They had spent around five hours at the islands, known as Senkaku in Japan and Diaoyu in China.

Japanese coastguard ships had urged the activists not to land, with officers boarding some of the vessels to question people. No arrests were made.

Taiwan, which also claims the islands, summoned Japan’s representative to protest against the “provocative” act.