Was Eta behind the bombings?

Was Eta, the militant Basque separatist moment, responsible for today's carnage at Madrid's railways stations?

Was Eta, the militant Basque separatist moment, responsible for today's carnage at Madrid's railways stations?

A major crackdown on the group by the Spanish government had been credited with blunting its activities in recent years, despite high profile attacks on holiday resorts last year.

The terror group has not admitted responsibility for today's attack, and Arnold Otegi, leader of the outlawed Batasuna party which is Eta's political wing, denied the Madrid blasts were its work and suggested "Arab resistance" elements were responsible.

He said that Eta always phoned in warnings before it attacks and there was no warning today.

If Eta does turn out to be responsible, the devastation in Madrid would be easily the highest death toll of any Eta atrocity since it began its campaign of violence more than 30 years ago.

British-based terrorism experts said they would not be surprised if Eta had resurfaced with a major attack, saying those who predicted its demise misunderstood how it worked.

But the scale of the bombings shocked even the most seasoned Eta-watchers.

Professor Paul Heywood, of the School of Politics, Nottingham University, said: "This is way, way bigger than anything Eta has ever done before. The scale of this is a big shock but the fact that there's been an attack isn't.

"No matter how often the Government said it has captured so many leaders of Eta or broken up commando units the nature of its organisation means it is never going to be beheaded in this way," he said.

Recent Spanish governments have been united in their determination to clamp down on Eta's activities, particularly since the 11 September attacks in the US.

Police targeting the group have arrested more than 600 people in the last four years and were widely reported to have extensively infiltrated its organisation.

The Government has also come down heavily on the Batasuna party which is often thought of as its political wing.

This strong-arm action by the Spanish authorities appears to have had some success with the death toll resulting from Eta attacks dropping to just three in 2003.

The Spanish election campaign prompted some Spanish commentators to question whether the terror group was lying dormant or whether it was a spent force.

Prof Heywood said: "Those who thought Eta was finished misunderstood how it is organised and how it works.

"It operates as a series of small commando units and no matter how many people are targeted they will always be able to strike as long as there are units still active.

"Even with a massive attack like today it could be undertaken with a relatively small number of people."

Dr Michael Reddy, Chairman of ICAS, a leading international behavioural risk management consultancy, said he did not think the Madrid attacks constituted a change of direction by Eta.

"Their actions do seem to be much more extensive and indiscriminate now, targeting public transport, than they have been in the past," he said.

"But I'd call it an escalation rather than a change in their tactics.

"In recent weeks there's been a trend for them to be seen as being less effective and this will change that.

"But there's no doubt that even in the Basque country this will be regarded with such vast revulsion that there will be a backlash."

The terror group is believed to have been responsible for the deaths of more than 800 people over the last 35 years.

Eta, which stands for Euskadi Ta Askatasuma, or Basque Homeland and Freedom, was first established in the 1950s to fight for the independence of the Basque country in the far north of Spain and south-west corner of France.

It was founded in the wake of General Franco's moves to ban the Basque language and clamp down on the distinctive culture of the area.

Eta's international profile was firmly established in 1973 with its spectacular assassination of Franco's right-hand man, Admiral Luis Carrero Blanco.

The group's bloodshed hit its peak in the 1970s and 1980s with scores of car bombs and gun attacks against judges, politicians and police, as well as a concerted targeting of the Spanish tourism industry.

One of the worst atrocities committed by Eta before today was a bomb in a Barcelona supermarket on 19 June 19, which left 21 people dead and 45 injured.