MADRID , Spain ( CNN ) -- Spanish police arrested 12 people Thursday on suspicion of Islamic terrorist activities , authorities said . Firefighters extricating bodies from one of the trains that exploded near Atocha station , Madrid , in 2004 . Eight of them , all Moroccans , were arrested early Thursday . They are suspected of providing cover for five fugitives from the Madrid train bombings four years ago and also of involvement in financing and recruiting of Islamic terrorists , according to the ministry statement and a judicial source . Later Thursday , police arrested four more people -- three Moroccans and an Algerian -- in their prison cells for similar charges . Additional details about those four were not immediately released . The operation was conducted on orders of Judge Baltasar Garzon , an investigating magistrate at Spain 's National Court , which handles cases of terrorism . The suspects range in age from 23 to 56 . Four are from Tangiers , just across the Mediterranean from mainland Spain , and the others from elsewhere in Morocco , the ministry said . The Madrid train bombing took place on March 11 , 2004 , killed 191 people and wounded 1,800 . In the days and months that followed , police arrested a number of suspects in and around Madrid , but determined that a small number of suspects had escaped . Authorities have long suspected that they had help getting out of the area with the assistance of a secretive group of accomplices . The main Madrid train bombing trail ended in 2007 with the convictions of 23 men . Five of them were later acquitted by the Supreme Court . A small number of other suspects have yet to stand trial . Since the bombings , Spanish police have arrested dozens of Islamic terror suspects , who are accused of activities ranging from plotting attacks to providing financing to recruitment .
Those held suspected of providing cover for fugitives from Madrid train bombings . Charges also cover involvement in financing and recruiting Islamic terrorism . Madrid train bombing took place on March 11 , 2004 , killed 191 people . The subsequent trial ended in 2007 with the convictions of 23 men .