MADRID (Reuters) - Spain's High Court has found 20 Islamic radicals guilty of crimes linked to a plot to blow up the court's Madrid building, court officials said on Wednesday.

The sentences for the men, mainly Moroccans and Algerians, will be announced later on Wednesday, but 18 have been found guilty of being members of a terrorist organisation and another two of assisting terrorists, the officials said.

Thirty suspects arrested in October 2004 had been charged with crimes linked to the plot to blow up the High Court.

In March 2004, a separate group of Islamist bombers killed 191 people in attacks on Madrid trains, for which 21 men were jailed.

Prosecutors had asked for sentences from 8 to 43 years for the High Court plot.

(Reporting by Teresa Larraz)