French and Spanish police detained two people and found weapons and explosives in a raid Thursday on a villa in southwest France targeting Basque separatist group ETA, Spanish authorities said.

The operation by Spanish Civil Guards working with French police was directed against ETA's technical and logistic structure, Spain's Interior Ministry said.

A French couple was detained, and police found an "arsenal of arms and explosives" and material used to make fake license plates, the ministry said in a statement. It didn't elaborate.

A few dozen officers were involved in Thursday's operation in the center of the Atlantic Coast resort of Biarritz, including scientific police cloaked in white and masked special police forces.

ETA killed 829 people in its Basque independence campaign but declared a permanent cease-fire in 2011. It has not disbanded. It regularly stored its arms and ammunition in southern France.