MADRID, Spain (CNN) -- A judge in Spain has freed most of 12 suspected Islamic terrorists he ordered to be arrested a week earlier, saying there was not enough evidence to hold them, an official said Tuesday.
Police seized the mainly Moroccan men last Thursday -- including four already in prison on other charges -- for allegedly aiding five fugitives from the 2004 Madrid train bombings, and for helping finance and recruit Islamic terrorists.
Two were released shortly afterwards and on Monday, during a court appearance for the remaining 10, judge Baltasar Garzon found insufficient evidence to continue holding the others, a court spokeswoman told CNN.
Six suspects were released Monday, although reports said they were required to appear regularly before authorities so their whereabouts are known. The four had already been in jail, remain in custody facing other charges, she said.
Garzon ordered the arrests last week on the advice of police investigators. But without sufficient evidence, he was unable to hold the suspects any longer on the charges, the spokeswoman said.
The Madrid train bombings killed 191 people and wounded more than 1,800 in coordinated attacks against four commuter trains on March 11, 2004.
Since then, Spanish police have arrested dozens of Islamic terror suspects, accusing them of activities ranging from plotting attacks to providing financing to recruitment.