Eta reeling after arrest of military commander in France

The man who is said to be Eta's top military commander was arrested in France early yesterday, in a Franco-Spanish police operation that produced eight further detentions and dealt a heavy blow to Europe's most intransigent armed separatist group.

Jurdan Martitegi, the third senior figure in the Basque organisation to be captured in five months, was arrested as he drove to a rendezvous near the southern French town of Perpignan.

Martitegi is said to have been preparing a new cadre of militants to mount terror attacks in Spain. Police seized three pistols and suspected bomb-making material. They also said they had rounded up another six suspects in the Basque country as part of the same operation.

Martitegi, 28, had gone into hiding in France to evade a Spanish arrest warrant issued in connection with several terrorist attacks in 2007, including the killing of a policeman.

Detained with him yesterday was Alex Uriarte Cuadrado, who had driven to the rendezvous from Spain, little realising that he was being tailed by Spanish police on the orders of the anti-terrorist examining magistrate, Baltasar Garzon, back in Madrid.

Spanish police crossed the Pyrenees and linked up with their French counterparts, who had been following Martitegi and another militant, Gorka Aspitarte, as they drove in a stolen vehicle with false plates to the tranquil village of Montauriol, in the foothills of the Pyrenees south-west of Perpignan. This Franco-Spanish cooperation – strengthened in 2007 to allow Spanish security forces to operate on French soil – was crucial to the operation's success, and that of previous recent police action. Three top leaders detained since November were all picked up France.

This new level of cooperation was sealed during Nicholas Sarkozy's stint as French interior minister, following decades of mutual suspicion between the two countries over how to deal with armed separatists, many of whom had found a safe haven in France. Alfredo Perez Rubalcaba, Spain's interior minister, was said to have been in constant contact with his French counterpart Michele Alliot Marie throughout Saturday.

Eta's previous military leader, Aitzol Iriondo, was arrested in France in December, just three weeks after his predecessor, Garikoitz Aspiazu, known as Txeroki, had been caught, having been tailed by police for a month. Another Eta leader, Javier Lopez Pena, was arrested last May.

All were considered hardliners opposed to Eta's nine-month ceasefire that ended with the bombing of Madrid airport in December 2006, which killed two people.

It appears Eta militants can no longer count on the cushion of local sympathy in activist circles that they may once have enjoyed. The organisation is thought to be riven with disagreements over whether to resurrect the process of dialogue with the authorities that was shattered by the 2006 airport bombing.

Mr Rubalcaba for his part was unequivocal on this: "Dialogue is in the past and the past never returns. The only question is whether Eta stops of its own volition or because we force it."