A Spanish court on Thursday overturned the convictions of four people found guilty in connection with the 2004 Madrid train bombings, drawing protests from victims of Europe's deadliest Islamist attack.
The court overturned a 2007 ruling, which found three of the men guilty of being members of an Islamist cell that carried out the bombings that killed 191 people and wounded more than 1,800.
All four were among 21 people convicted last year of blowing apart four morning commuter trains in attacks prosecutors said were inspired by, but not directed by, al Qaeda.
Relatives of those killed said they were baffled by the Supreme Court's decision, which also upheld the acquittal of "Mohamed the Egyptian," Rabei Osman Sayed Ahmed, who was accused by prosecutors of being one of the masterminds, the Reuters reported.
"The decision to grant them acquittals is completely bizarre. We all knew this was a jihadist cell," said Pilar Majon, head of a victims' group, whose son died in the attack.
Twelve-year sentences imposed on Syrians Basel Ghalyoun and Mouhannad Almallah Dabas for belonging to a terrorist group were set aside. Moroccan Abdelilah Fadual El Akil saw his 9-year sentence for belonging to an armed group overturned.
Raul Gonzalez, a Spaniard, was spared a 5-year sentence for supplying explosives.
The court cited a lack of evidence in the cases of the Syrians, the Moroccan and Gonzalez. The court also upheld the acquittal of the Egyptian, saying he had already been convicted of the offence in Italy.
Included in Thursday's appeal ruling was a decision to sentence Antonio Toro, also a Spaniard, to four years imprisonment for trafficking explosives.