Japan's Coast Guard Sunday dispatched patrol ships and aircraft after spotting a boat carrying Chinese activists to a group of disputed islands claimed by Japan, China and Taiwan.
"We have spotted a boat near the Japanese territorial sea on the western side of the islands," said a coast guard official based in the southern Japanese island chain of Okinawa.
The Coast Guard sent patrol ships and planes to the area and gave warnings to the boat, said the official.
The vessel briefly entered Japanese waters but left following the warnings, Kyodo news agency said.
The boat carrying four Chinese activists protesting against Japan's control over the islands — called the Senkaku Islands in Japan and Diaoyu in China, which lie between Taiwan and Japan — set off Friday from China's Fujian province, Jiji Press reported.
The activists tried to land on the islands but were blocked by the Japanese coast guard, it said.
Japan claimed the islands in 1895 but they were temporarily put under US control after World War II and returned to Japan in 1972 together with Okinawa.
In the early 1970s China and Taiwan made claims to the islands after oil deposits were confirmed in the area by a United Nations agency.
In March 2004 Japanese authorities arrested and deported seven Chinese activists after they went to the islands, causing a diplomatic row with Beijing.
