As of 2:55 PM CNN is running this breaking <$Ad$>headline: "Spanish interior minister says new line of Madrid blast investigation opened after police find van with detonators and Arabic-language tapes. Details soon."

Frankly, this makes a lot of sense. I don't know much more about the Basque separatist movement than one can glean over the years from the American press. But I have no recollection of the ETA mounting an operation which came even remotely close to accounting for this amount of loss of life and casualties.

My recollection is of bombings and other forms of terrorism on the scale of the old IRA. Horrific, certainly, but significantly different from September 11th sort of stuff.

And the multiple, simultaneous detonations is a hallmark of al Qaida, or Islamist groups operating under that broad umbrella.