A Taiwanese fishing boat sank Tuesday after colliding with a Japan Coast Guard vessel during an early morning chase about 10 km south of disputed islets north of Okinawa, coast guard officials said.

The Lianhe Hao's three crew members and 13 passengers were immediately rescued by the 966-ton patrol ship Koshiki, coast guard officials said.

The collision took place near Uotsuri Island, one of the uninhibited Senkaku Islands under Japanese control. The chain of islands — called Diaoyu in China and Tiaoyutai in Taiwan — is claimed by all three countries and has been a constant source of diplomatic friction with Beijing and Taipei.

In a telephone interview, a coast guard official in Okinawa quoted the Lianhe Hao's passengers as saying they had come to the area for fishing, not political reasons. No other details were immediately known.

The Lianhe Hao was spotted within Japanese waters close to the island early Tuesday. As the Koshiki closed in for a visual inspection to confirm its identity, the Taiwanese ship took off and the Koshiki gave chase, the officials said.

At some point during the chase, the Lianhe Hao suddenly swerved to starboard and hit the Koshiki's port bow, according to the coast guard. The Lianhe Hao sank around 3:23 a.m.

The boat's crew and passengers were later transported to Okinawa's Ishigaki Island, where they underwent medical checks and were questioned by the coast guard.

The Senkakus are controlled by Japan, which keeps at least one coast guard ship on patrol 365 days a year. Activists from China, Hong Kong and Taiwan have repeatedly tried to approach or land on the islets in protest.

In March 2004, seven Chinese activists landed on Uotsuri and damaged a shrine built by Japanese nationalists. Japan arrested and deported them, an incident that raised diplomatic tensions with Beijing.