LONDON - ENVIRONMENTAL activists used speed boats and climbing ladders to board a ship carrying coal to a power station in southeast England on Monday, occupying the vessel for several hours.

Campaign group Greenpeace said 10 activists made their way on to the ship making its way to the German utility E.ON's Kingsnorth Plant to protest the use of coal, which it called 'the most climate-damaging fuel known to man'.

Greenpeace said it ended the protest after four of its activists, who were camped out on the ship's foremast, were served an injunction. Six other activists had been arrested earlier.

Police in Kent, where the Kingsnorth Plant is located, said only that they were questioning 10 people in connection with the incident.

Kingsnorth, where E.ON is planning to replace its existing plant with two new coal-fired units, has been a magnet for environmental protesters.

In October 2007, six climate-change daubed paint on the 656-foot (200 meter) chimneystack at Kingsnorth. In their trial last year, the group's lawyers argued they had a lawful excuse for their actions because they were trying to prevent climate change from causing greater damage to property around the world.

The trial became a platform for environmentalists and scientists to give their views on climate change. Jim Hansen, head of Nasa's Goddard Institute for Space Studies and science adviser to Al Gore, testified at the trial and called for an immediate halt to the building of new coal-fired power stations.

E.ON says it is proposed coal-fired units would be cleanest ever built in the UK. -- AP