France, Spain say arrests, seizures have hit ETA hard

A series of arrests and arms seizures in France have dealt a heavy blow to Basque separatist group ETA but the militants still pose a threat, French and Spanish officials said Wednesday.

Earlier this month, French police arrested three armed ETA suspects in a ski resort and followed up the arrests by uncovering 13 separate caches of arms and explosives in isolated regions across southern France.

"These finds deprive ETA of an arsenal" French Interior Minister Brice Hortefeux told reporters after a meeting in Paris with Spanish Interior Minister Alfredo Perez Rubalcaba.

More successes were expected in the next few days, he said but gave no details.

French and Spanish police discovered the 13th cache of arms, which included 18 kilos of explosives, small arms and ammunition, Wednesday, Spain's government said in a separate statement.

Rubalcaba praised cooperation between French and Spanish security services.

"It will enable us to resolve this problem very soon, which is the most significant problem facing Spain at the moment, the problem of ETA" he said.

But the threat from the militant group remained, he said. 

"We cannot lower our guard."

Hundreds of kilos of explosives, 15 bombs of a kind that could be used in car bombings, 18 handguns and thousands of rounds of ammunition as well as stolen blank number plates and administrative documents have been uncovered.

Last month ETA celebrated the 50th anniversary of its secret foundation during the Franco dictatorship. But the organisation, blamed for around 800 deaths over the decades, has been weakened by the arrest of leaders and a slide in political support.

ETA militants have long sought refuge in the Basque country of southwestern France but have recently extended their range further north and into eastern France.

Security officials say ETA has been forced to change tactics as arrests have thinned its numbers and it appeared to have become more flexible, with a lighter organisation.

"They have drawn the lessons from arrests in the past. They've put an end to structures they've had in place for years and years" Anne Kostomaroff, head of the anti-terrorism section of the prosecutor's office, said.

But recent attacks, including bombings in the northern Spanish city of Burgos and the Mediterranean island of Mallorca, show it is still capable of mounting operations.

Hortefeux said 172 ETA members or associates were currently being held in France and he said the latest seizures suggested the organisation still posed a threat.

"We should not underestimate ETA's capacity to cause trouble and its willingness to kill" he said. "These arms finds showed attacks were being prepared."