Chinese patrol boats expelled several Japanese ships from waters near an uninhabited chain of islands in the East China Sea that is claimed by both countries, the official Xinhua news agency said.

The Japanese ships, whose number was not specified, were intercepted by four vessels from China Marine Surveillance, Xinhua said, without commenting on what was done to make them leave the archipelago.

"If Japan continues down its current wrong path and takes more erroneous actions and creates incidents regarding the Diaoyu Islands and challenges China, China will definitely take strong measures to respond to that," Chinese Deputy Foreign Minister Zhang Zhijun said last Friday.

Japan, which refers to the archipelago as the Senkaku Islands, is the defacto administrator of the territory and surrounding waters.

Tensions between Beijing and Tokyo have boiled over in recent weeks following Japan's purchase of three islets in the chain, which sparked violent demonstrations in Chinese cities and the suspension of events commemorating the 40th anniversary of the two countries' renewal of diplomatic ties.

Dozens of Japanese firms with operations in China - from automobile manufacturers to restaurant chains - have decided to suspend their activities out of fear of attacks.

Beijing says Japan appropriated the islands illegally during the First Sino-Japanese War of 1894-95. EFE