Spanish police arrested the leader of banned Basque separatist party Batasuna today, a Batasuna official said.
Spain's High Court ordered the arrest of Arnaldo Otegi on charges of praising terrorism in 2003 at a demonstration to commemorate the death of an Eta rebel, court officials said.
His arrest came just three days after Eta broke off a ceasefire it had declared in March last year.
News of the arrest came just minutes before Mr Otegi was due to start a news conference in the Basque city of San Sebastian.