Italian police uncovered 100 kilograms of explosives during a weekend raid on a house believed to be a hideout of the Red Brigades terrorist group. Investigators say the raid was a decisive blow to the organization.

The raid was carried out on a basement near Rome's main railway station as part of a wide-ranging counter-terrorism operation. Italian police say they also found 200 detonators as well as computer disks and documents described as being of "major importance."

Police followed a trail to the house based on information obtained following the arrest in October of nine alleged members of the Red Brigades in Florence.

Investigators believe the explosives found in the Rome raid represent the entire stock held by the Red Brigades organization. They say the Saturday raid was a decisive blow to the organization and will have a psychological impact on leftist militants.

Some of the documents found in boxes and bags belonged to Nadia Desdemona Lioce, an alleged Red Brigades terrorist, who was arrested in March during a train shootout. Police say they found a notice claiming responsibility for the 2002 killing of government consultant Marco Biagi in Bologna.

The arrest of Ms. Lioce re-launched the inquiry into the Biagi murder and that of another Italian labor ministry official, Massimo D'Antona, who was killed in Rome in 1999.

The Red Brigades-Combatant Communist party claimed responsibility for both crimes. The group is an offshoot of the Marxist group that carried out hundreds of bloody attacks in Italy in the 1970s and 1980s.

The killing of the two government advisers prompted fears in Italy of a resurgence of the long-dormant group. Authorities say some 140 of the original Red Brigades activists are at large.