MADRID, Spain (CNN) -- A Spanish court Wednesday convicted 20 men, mainly Algerians and Moroccans, of Islamic terrorist activity, but none was found guilty of the more serious charge of an alleged plot to destroy Madrid's anti-terrorism courthouse with a truck bomb, according to a copy of the sentence viewed by CNN.
Those convicted were part of a group of 30 defendants who went on trial last October. The three-judge panel hearing the case -- in the very courthouse that prosecutors alleged was the target of the truck bomb -- began their deliberations for a verdict after the trial concluded on Jan. 14.
Eighteen of the defendants were convicted of belonging to a terrorist group and two others were convicted of collaborating with a terrorist group. In addition, two of the men were found guilty of an additional charge of document forgery, the sentence said. Their sentences range from seven to 14 years.
But the court found "non-existent the crime of conspiracy to commit a deadly terrorist attack," the sentence said.
The sentence noted that Moroccan defendant Abderrahmane Tahiri, alias Mohamed Achraf, age 34, had "conceived of the idea of executing a terrorist attack with an explosives-laden vehicle against the National Court, as an emblem of the fight against terrorism."
But the court said this did not constitute conspiracy under Spanish law because it was no more than an "undeveloped individual plan" by Tahiri.
"The conception of a possible terrorist objective does not constitute the existence of conspiracy, but is an activity that is part of belonging to a terrorist group," the sentence said.
Tahiri got the maximum sentence handed down, 14 years, as leader of the terrorist group, the sentence said.
The 20 men convicted had created Jihadi terror cells in prison -- where many of them were already serving time for other crimes before their arrests in this case -- to recruit other prisoners for terrorism, according to court sources.
The remaining 10, mainly Algerians, were acquitted of all charges. Nine of them were acquitted of membership in a terrorist group, and one was acquitted for collaboration with a terrorist group, the sentence said.
The prosecution argued that that alleged truck bomb plot aimed to kill hundreds of judges, prosecutors, support staff and police officers who work daily at the National Court, and also to destroy files against other Islamic terrorist suspects, including those linked to the Madrid train bombings.
Prosecutors based their case on testimony and documentation provided by a Moroccan man operating as a police informant, and on wiretaps and intercepted correspondence between some of the suspects, according to a court document and a court source.
Most of the defendants were arrested in October 2004, about six months after the March 11, 2004 Madrid train bombings that killed 191 people and wounded 1,800 others.
All of the defendants insisted on their innocence at arraignments and other pre-trial hearings.
At the time of the arrests, an attack on the courthouse "would have been easy," a court source said. There are streets on three sides of the courthouse, and a main street runs next to the building.
The courthouse has since increased security, installing thick metal barriers to block traffic on the side and back of the building. E-mail to a friend
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