TAIPEI (AFP) - A boat carrying a group of Taiwanese activists heading for disputed Japanese-controlled islands turned back today before reaching their destination, Taiwan's coastguard said.

The vessel turned back at 11am and was expected to arrive back at its north Taiwanese port a little more than seven hours later, a coastguard spokesman said.

Japan's coastguard said it fired water cannon at the boat.

"After entering our country's contiguous zone, the vessel with foreign activists on board continued sailing east. So our patrol boat carried out restrictions on the vessel such as blocking its path and discharging water," it said in a statement.

The coastguard said at the time of the confrontation, the Taiwanese boat was around 32km west-southwest of the Senkakus, claimed by Taiwan and China as the Tiaoyus and Diaoyus, respectively.

It also confirmed Taiwanese coastguard statements that the boat was headed away from the flashpoint.