More than 800 people are alleged to have been killed by terrorist activities of the separatist group Eta. Spanish officials say that Batasuna is the mouthpiece for Eta, and have imposed a crackdown.
Spanish police have arrested the entire alleged leadership of the banned Basque separatist party, Batasuna.
Twenty-two people were detained in the town of Segura on orders from Spain's top anti-terror judge, Baltasar Garzon.
The security forces raided a Batasuna meeting at which the party's old guard was alleged to be transferring control to new leaders.
Mr Garzon led moves to outlaw Batasuna five years ago, accusing it of being a front for armed separatists Eta.