Twenty-one of 28 defendants were found guilty Wednesday in the 2004 Madrid train bombings that killed 191 people during the busy morning rush hour, but one accused ringleader was acquitted in connection with Europe's worst Islamic terror attack.

Judge Javier Gomez Bermudez read the verdicts in a quiet courtroom as the defendants awaited their fates behind a bulletproof glass enclosure.

Bomb-sniffing dogs and police helicopters patrolled outside the Madrid court, where 21 were convicted of murder or lesser charges stemming from hard evidence of the backpack bomb attacks that killed 191 people and wounded more than 1,800 on March 11, 2004, as commuters swarmed the rail stations and trains at the peak of rush hour.

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Three lead suspects each were handed sentences that stretched into the thousands of years, but Rabei Osman, an Egyptian accused of helping orchestrate the attacks, was acquitted. His lawyer had argued during the five-month-long trial that wiretapping evidence was questionable in suggesting Osman, who is in jail in Italy, had allegedly bragged in a phone conversation that the massacre was his idea.

Victims of the attacks said they were shocked and saddened by the court's decision, which they saw as far too lenient.

"The verdict seems soft to us," said Pilar Manjon, whose 20-year-old son was killed in the blasts and who has become a leader of a March 11 victims' association. "I don't like it that murderers are going free."

Three lead suspects — Jamal Zougam, Othman Gnaoui and Spaniard Emilio Suarez Trashorras — were convicted of murder and attempted murder and received sentences ranging from 34,000 to 43,000 years in prison, although under Spanish law the most time they can spend in jail is 40 years. Spain has no death penalty or life imprisonment.

Zougam and Gnaoui are both Moroccans, the first convicted of placing at least one bomb on one of the trains, and the latter of being a right-hand man of the plot's operational chief. Trashorras, a Spaniard, is a former miner found guilty of supplying the explosives used in the attacks.

An Italian appeals court on Monday upheld Osman's conviction there, but shaved two years off his prison term, sentencing him to eight years.

Osman watched the Spanish proceedings on a videoconference link from the Justice Palace in Milan. The Europa Press news agency reported that he broke down in tears and shouted "I've been absolved! I've been absolved!" following the Spanish verdict, citing journalists and other observers inside the court.

Four other top suspects — Youssef Belhadj, Hassan el Haski, Abdulmajid Bouchar and Rafa Zouhier — were acquitted of murder but convicted of lesser charges including belonging to a terrorist organization. They received sentences of between 10 and 18 years.

Fourteen other people were found guilty of lesser charges, such as belonging to a terrorist group, and six others accused of lesser crimes were acquitted.

Much of the evidence against the men was circumstantial. Bouchar, for instance, had been seen on one of the bombed trains shortly before the attack, but at trial no one could positively identify him and there were no fingerprints or other forensic evidence placing him at the scene.

A senior court official privy to the decision-making told The Associated Press following the verdict that the case against Osman was "flimsy," and that there was "no hard evidence" that Belhadj or Haski were masterminds. The official spoke on condition of anonymity.

Circumstantial evidence is admissible in Spanish court, but the judges may have avoided relying heavily upon it because of a number of high-profile terror cases that were overturned on appeal, including one involving a Spanish cell accused of involvement in the attacks on Sept. 11, 2001, said Fernando Reinares, until recently the chief counterterrorism adviser at the Interior Ministry.

He said the judges in the case used a narrow approach to the law and warned that Spanish courts would have to change their rules of evidence if the country was to defeat Islamic terrorism.

"Islamic terrorism ... leaves a different kind of footprint," said Reinares, now head of the terrorism studies program at the Elcano Royal Institute, a Madrid think-tank.

The trial was perhaps never going to bring the verdict some were looking for, since the seven men considered the true ringleaders of the March 11 attacks were not in the docks. They all blew themselves up at a safe house on the outskirts of Madrid as police moved in to arrest them three weeks after the massacre.

Three other men are still fugitives, though two of those are suspected of having later killed themselves in suicide attacks against U.S.-led forces in Iraq.

The March 11 suspects — both dead and alive — were mostly young Muslim men from a hodgepodge of different backgrounds who allegedly acted out of allegiance to al-Qaida to avenge the presence of Spanish troops in Iraq and Afghanistan, although Spanish investigators say they did so without a direct order or financing from Osama bin Laden's terror network.

Spanish authorities had been on the group's trail in the months before the attacks, but had failed to grasp what they were plotting, mistaking the coded language in tapped phone conversations as that of petty criminals arranging a drug deal.

The attacks will be forever etched in Spain's collective memory, much as Sept. 11 conjures up so much pain for Americans. March 11 — a day of hellish carnage, wailing sirens and cell phones going unanswered amid the wreckage of blackened, gutted trains — was Spain's worst tragedy since its civil war.

It also arguably toppled the government of then-Prime Minister Jose Maria Aznar, who initially blamed the Basque separatist group ETA for the bombings, even as evidence of Islamic involvement emerged.

That led to charges of a cover-up to deflect attention away from Aznar's support of the U.S. invasion of Iraq, one of the reasons the bombers gave for carrying out the attack. Aznar's Popular Party was voted out of power in elections three days after the bombings, and the victorious Socialists quickly brought the Spanish troops home.

Even since its defeat, members of the Popular Party have insisted that ETA may have played a role, a hypothesis that was totally rejected by the court.

Prime Minister Jose Luis Rodriguez Zapatero, the beneficiary of that political upheaval, welcomed Wednesday's verdicts. "Justice was rendered today," he said.

"The barbarism perpetrated on March 11, 2004, has left a deep imprint of pain on our collective memory, an imprint that stays with us as a homage to the victims," he said.

At least 12 others reportedly were involved in the attacks, seven of whom had a role in the planning stages and about five others who either fled to Iraq or were killed. At least two died in homicide bombings, FOX News' Greg Palkot reported from outside the courtroom as the verdicts were read.

FOX News' Greg Palkot and The Associated Press contributed to this report.