TOKYO - Two Japanese nationals have landed on a disputed island claimed by Tokyo, Beijing and Taipei, despite warnings from the coastguard to stay away, an official said Friday.
Hitoshi Nakama, a local politician from Ishigaki, Okinawa, and another person went ashore on Kitakojima, one of a group of islands making up what Japan knows as Senkaku and China calls Diaoyu.
"Despite our warning, they dived into the sea from a fishing boat and reached the island," a Japanese coastguard official said, adding that the two stayed for 90 minutes before leaving.
The case is under investigation by both the coastguard and police, the official said.
The Japanese government controls the strategically-coveted but uninhabited islands and is resolute about the territory being Japanese, but prohibits people from going there without permission in a bid to cool tensions.
In Beijing, foreign ministry spokesman Liu Weimin, hit out at the landing.
"The Diaoyu Islands and affiliated islands have been China's inherent territory since ancient times," he said.
"The illegal acts of the Japanese right wing activists severely violate Chinese territorial sovereignty. The Chinese side has made solemn representations and protests to the Japanese side."
The islands, which lie in rich fishing grounds and may harbour valuable mineral reserves, were the scene of a nasty spat between Tokyo and Beijing in 2010 when Japan arrested a Chinese trawlerman who had rammed two of its patrol vessels.
Tokyo's controversial nationalist governor has said he is in negotiations to buy the islands from their private Japanese owner on behalf of the metropolis, charging the government is not doing enough to protect Japanese territory.
Earlier this week Taiwanese vessels tangled with Japanese patrol ships in waters near the islands.