Spain's supreme court has overturned the convictions of four of the 21 people found guilty of involvement in the 2004 Madrid train bombings that killed 191 people.

The four men had been convicted of charges ranging from membership of a terrorist group to supplying explosives.

The court also upheld a lower court's acquittal of one of the alleged masterminds of the al-Qaida inspired attacks, Rabei Ousmane Sayed Ahmed, also known as Mohammed the Egyptian.

The Supreme court said Thursday there was not enough evidence to condemn him as an organizer of the attack.

The early morning bombing of four packed commuter trains was the deadliest terror attack in the west since the September 11 attacks in the US in 2001. 


Some information for this report was provided by AFP, AP and Reuters.