French and Spanish authorities have arrested at least 18 suspected Basque separatists.
Police in southwestern France say the joint operation against the armed group ETA has also uncovered stockpiles of weapons and explosives, as well as large sums of money. Seven homes have been searched and the raids are continuing.
Most of the arrests were made in French Basque areas, with one arrest in Spain. Two of the detainees - Mikel Albizu Iriarte and Soledad Iparraguirre - are veteran ETA leaders from Spain living in France illegally since the early 1990s.
The European Union and the United States consider ETA a terrorist organization. The group began its campaign of violence in 1968 to press for an independent Basque state in southwestern France and northern Spain. ETA attacks have killed more than 800 people.