Further weakening the Basque separatist group, French police have arrested a top military leader of ETA.

Spanish officials have said that Ibon Gogeascotxea, who according to Madrid is the group's most senior military leader, was arrested with two other ETA members in Normandy in northwestern France.

The other two suspects -- Beinat Aguinalde Ugartemendia, 26, and Gregorio Jimenez Morales, 55 -- were part of a commando unit ready to enter Spain and stage attacks there, said Spanish Interior Minister Alfredo Perez Rubalcaba.

BBC News quotes Rubalcaba as saying that they had gone to Normandy to "say goodbye to the military chief, who gave them their final instructions as ETA has a habit of doing."

Formed under the oppressive regime of Gen. Francisco Franco, Euskadi ta Askatasuna (Basque Homeland and Freedom), for four decades has fought for an independent state in northern Spain and southwest France and has been blamed for around 850 deaths. It is considered a terrorist organization by the European Union and the United States.

He is accused of helping place bombs at the Guggenheim Museum in Bilbao in 1997 in a plot to kill King Juan Carlos, Spanish officials said.

Seizing half a ton of explosives, Police in Portugal and France arrested four suspected ETA militants in January and in February officials raided a suspected ETA bomb-making base.

Spanish Prime Minister Jose Luis Zapatero, who is steering a hard-line course against the group, after the attacks said his goal was to crush ETA. (With Inputs from Agencies)