Ships collide off Antarctica

A boat carrying a group of anti-whaling activists has collided with a Japanese whaling vessel in the Antarctic Ocean.

The environmentalists say they were trying to prevent the Japanese ship from dragging a whale on board when the collision occurred.

Japan says the vessel was rammed on purpose.

It is the latest in a series of dramatic confrontations between environmentalists and Japan's whalers, in some of the most dangerous waters in the world.

Phil Mercer reports.