MADRID BOMBINGS: The Belfast Irish bar on Calle Juan de Bilbao has an assortment of political posters, collecting jars on the counter among the tapas, and a plaque behind the bar calling for the return to the Basque country of Eta's 700-odd prisoners.
On the television set, the Basque-language channel is bringing reports and images from Madrid of the aftermath of Thursday's carnage.
"This is all about votes," says the barman, as the umpteenth bloodied victim is borne across the screen. "If it's Eta, then Aznar's lot get more votes." But if it's al-Qaeda? He pulls a face and gives a thumbs-down.
Like many people inside and outside the Basque country, he had made the calculation that the fate of Jose Maria Aznar's People's Party government is riding on the issue of who was responsible for Thursday's bombings.
The prime minister's support for the invasion of Iraq in the teeth of overwhelming public scepticism could cost his followers dear if the attacks were laid at the door of a group from the Middle East. However, if Eta was shown to be behind them, it could give retrospective justification to his equally stubborn repression of Basque separatism.
For Eta's supporters and apologists, that alone is justification for believing that the government is trying to blame its gudari - fighters - for cynical reasons.
Calle Juan de Bilbao, in the picturesque old quarter of San Sebastian, is the epicentre of radical Basque nationalism. The windows of its bars and restaurants are plastered with posters demanding self-determination. Everywhere there are signs of the increasingly hard line taken against the separatists in recent years.
Support for radical nationalism can only be expressed furtively these days. From a doorway a few metres down the street from the Belfast Irish pub, a group of four young people emerge with a banner demanding self-determination, which they proceed to string across the street.
"The police will be along soon to tear it down," says a young man before referring questions on to another wearing a hooded jacket who, like his friend, does not want to give his name. Speaking before the group issued its denial yesterday, he gives a string of reasons why Eta would not have carried out the bombings.
"Eta has never sought to kill civilians and it always gives warnings. The worst mistake it ever made was Hipercor [the bombing in 1987 of a supermarket in Barcelona\]. But what happened there was that the police did not take the warning seriously. This would be a qualitative change. It's not believable."
At this point, Josetxo Ibazeta wheels his bike past. Until his party was outlawed, Mr Ibazeta was the leader of the Batasuna group on the city council. The Spanish police say Eta's operational arm recently acquired a new young leader and claim that since the end of last year they have thwarted two attempts by the group to cause massive explosions in the capital, the most recent involving half a tonne of explosives. Is a "qualitative change" so unbelievable?
"But the target [of the most recent thwarted attempt\], as far as we know from what the police have said, was an industrial zone," Mr Ibazeta says. "The bomb was to have been set off at dawn - and there would have been a warning. There's a big difference between that and attacking trains carrying people into work from working-class areas."
The head of the Basque government, Juan Jose Ibarretxe, had been angered by Eta's silence on the question of responsibility. Closing a press conference in the Basque capital of Vitoria yesterday, he said: "We have the right to know the truth."
But, even when the Eta denial came, not everyone in the Basque country was ready to believe it.
As thousands gathered last night in San Sebastian to demonstrate against the attacks, one of the protesters, Juan Luis Aramburu, said: "People who kill lie too. Lying is nothing to those who kill."