Two of the men were convicted of attempted murder for throwing hand grenades during a standoff with police and given sentences of 15 and 13 years.

Among the defendants was Mohammed Bouyeri, 27, the convicted murderer of filmmaker Theo van Gogh, who has already been sentenced to life in prison for the 2 November, 2004 murder.

Bouyeri was found to be a leader of the group but judges said he could not be punished further.

The group's goal was "stirring up, and or inciting hatred, and or threatening" non-Muslims, the judges said. "Who sows hate lays the basis for crimes that can cause grave fear," said judge Rene Elkebout, reading the ruling. Such crimes "strike at the heart of the democratic order", he said.

The heaviest sentences were given to Jason Walters - who has an American father - and Ismael Aknikh, who were found to have operated with premeditation when they threw a hand grenade that wounded 5 police officers on 10 November, 2004.