Spanish prosecutors called for rebellion and terrorism charges to be leveled against nine activists linked to pro-Catalan independence groups who were arrested Monday on suspicion they may have been preparing to commit violent acts, possibly with explosives.
A Civil Guard police statement said the operation in Barcelona province was part of an investigation into the self-proclaimed Committees for the Defense of the Republic, a grassroots organization that favours northeastern Catalonia's independence from Spain.
In the past, the group has organised street protests and blocked road and rail lines. It is known by its initials, CDR.
Police said they carried out 10 raids and seized an abundance of material and substances they believe could be used to make explosives.
If confirmed, it would be a considerable blow to Catalonia's mainstream independence movement, which is proud of its overwhelmingly peaceful approach since it began gathering momentum in 2011.
National Court prosecutors said the raids were aimed at gathering evidence to demonstrate the CDR's "advanced preparation for terrorist acts in connection with their secessionist aims."
They said the CDR's activities could have caused "irreparable damage given the advanced state of their preparations."