Spanish police have arrested the entire alleged leadership of the banned Basque separatist party, Batasuna.
Batasuna spokesman Joseba Permach was among those held
Twenty-two people were detained in the town of Segura. The raid, in Spain's northern Basque region, was ordered by top anti-terror judge Baltasar Garzon.
At the Batasuna meeting, the party's old guard is alleged to have been transferring control to new leaders.
Mr Garzon led moves to outlaw Batasuna five years ago, accusing it of being a front for the armed separatists, Eta.
Earlier this year, the Basque militant group Eta called off a 15-month ceasefire.
The raid in Segura is the latest operation in a four-month crackdown against Basque separatists that has included the arrest of Batasuna's leader, Arnaldo Otegi, on charges of "glorifying terrorism".
Among those detained on Thursday was Joseba Permach, who has acted as Batasuna's main spokesman since Mr Otegi's arrest.
He and his colleagues from the Segura meeting are expected to be transferred for questioning to Madrid, a judicial official told the AFP news agency.
The agency quoted the official as saying the group of 22 would face charges stemming from Mr Garzon's investigation into allegations that Batasuna financed Eta's activities.
Spain's Attorney General, Candido Conde Pumpido, welcomed the latest arrests, saying some of those held were accused of co-operating with an armed group.
The Segura raid was the latest operation in a four-month crackdown
"These activities cannot be tolerated, so if the police find out about them, as they did in this case in Segura, it seems prudent that they be ordered to intervene," he told Spanish public radio RNE.
A senior member of Batasuna, Pernando Barrena, criticised the arrests as an attempt by the governing Socialist party to bolster its standing ahead of elections next March.
Mr Barrena also told AFP the government was pursuing "revenge" against Batasuna because the group had taken a "firm line" in peace talks last year.
Before Batasuna was banned in 2003, it represented about 15% of the people in the Basque region on local councils and in the regional government.
The separatist militants of Eta are blamed for the deaths of more than 800 people during a four-decade campaign to set up an independent Basque state in northern Spain and south-western France.
Spain's socialist government has been quick to take a hardline approach against Eta to maintain electoral support.
The group is considered a terrorist organisation by Spain, the European Union and the United States.