BAYONNE, France – A vast police operation in France and Spain netted at least 18 suspected members of the armed Basque separatist group ETA and large stocks of weapons, authorities said.

Seventeen suspects were captured in towns in southwest France, and another was arrested in the northern Spanish city of Burgos, French police authorities said yesterday. Spain’s Interior Ministry put the number of suspects in custody at 21.The discrepancy with the French figure could not immediately be explained.

Spanish authorities said those detained included two well-known ETA leaders, Mikel Albizu Iriarte – alias Mikel Antza – and Soledad Iparraguirre, who uses the alias “Amboto.” They are a couple, have a son, and have been on the run since 1993.

Ms. Iparraguirre is considered one of the leading female members of the armed group. Mikel Albizu is thought to have been a top ETA leader for the last 12 years, since police devastated the organization by arresting most of its senior members.

Mr. Albizu managed to escape a police raid last April that netted an ETA logistics chief, Feliz Ignacio Esparza. The other suspects’ identities and nationalities were not immediately released.

Spanish officials described the raids as a major operation that will weaken the logistics of the group. ETA has since the 1960s carried out bombings and assassinations in Spain in a campaign to get an independent Basque state.

Spanish press reports said those in detention included Mikel Albizu Iriarte, who is thought to have been a top leader of the group for the last 12 years.

The suspect arrested in Burgos in Spain was thought to have planted bombs for ETA in September at power installations, French police said. His wife was among the 17 people picked up in several towns in southwestern France.

Police also uncovered seven separate stocks of weapons, including rocket launchers, assault rifles, munitions, and explosives.