In the aftermath of the bombings in Madrid, newspapers across Europe on Friday look at what happened the previous day and ask the questions who, and why?
The horror and the pity
Madrid's El Pais carries accounts by people caught up in the attack.
"Those who were able to walk got out and stampeded down the tracks," a 28-year old commuter says. "I stayed to help, to get the wounded out... I held a girl in my arms and we lost her... She died in my arms."
"There were wounded and blood everywhere, body parts, and people trapped in the wreckage," a man tells the paper.
"What struck me the most," the Swiss Tribune De Geneve quotes a tearful nurse as saying "were the mobile phones of the dead, which never stopped ringing."
"How easy it is to kill people on their way to work in the morning," Barcelona's La Vanguardia quotes a stunned bystander as saying as he contemplated the carnage.
But who did it?
Madrid's El Pais thinks it was ETA.
"This was the terrorists' way of reminding us of their existence."
But in Barcelona, La Vanguardia points out that, if so, then ETA has "adopted a new strategy of terror totally different from the one to which we are sadly accustomed".
A thought echoed by Le Monde in neighbouring France.
"The Basque group has usually warned the security services "so as to minimize civilian casualties, the paper points out."
And after its previous bloodiest attack, when 21 people died in a Barcelona supermarket blast in 1987, the paper says, ETA actually issued an apology.
Fellow-Parisian Liberation is also dubious although ETA "inevitably comes to mind first."
But "the massive scale of the Madrid attack," the paper argues, "is more in line with what is known of al Qaeda than with the methods of the Basque terrorists."
The Swiss Tribune De Geneve asks whether these are "the hideous convulsions of a weakened nationalist movement, or the provocation of the fanatical henchmen of al Qaeda, determined to punish Spain for its part in the American war on Iraq"?
Even a third possibility should not be ruled out, the paper argues, in the form of collaboration between ETA and Islamist groups.
Fellow-Genevan Le Temps is preoccupied with the same subject, and mourns the time when "the swine had the guts to claim responsibility without cheating".
These days, it observes, "terrorism appears to have become a form of expression in itself, nihilism's revenge on politics".
Spain's 11 September
In Germany, Sueddeutsche Zeitung believes that "this 11 March will mark Spain's memory in a similar way that 11 September 2001 has marked the memory of the USA and of the whole world".
The paper notes that the attacks came at a time when the Spanish authorities appeared to have scored some notable successes in their fight against ETA.
"Paradoxical as it may seem," it says, "this could precisely be the reason for the latest terror attacks, if indeed, as suspected, ETA is responsible."
The Frankfurter Rundschau says the bombings have created a greater sense of national unity.
"In Spain people are rallying as they have rarely done in the history of this country marked by civil war, dictatorship and nationalistic revolts," the paper says.
But in Austria, Der Standard is not so sure this will last.
"If the call for tough police state methods becomes too loud," it warns, "there is a possibility that the wounds left by Spain's Francoist past, which have not quite healed, will be ripped open again."
Its fellow-Austrian Die Presse says no security measures can provide protection from attacks such as the Madrid bombings because terrorism is "timeless".
"If it does not happen here and now," the paper says, "it will happen tomorrow somewhere else, because this is no longer about negotiations or concrete goals but rather chaos, suffering and cruelty."
The view from 'new Europe'
After the Madrid attack, Hungarian Nepszabadsag says, "Europe is faced with greater dilemmas than America after 11 September".
If the attack was the work of Basque separatists, the paper argues, "then it highlights the failure of most European states to find a working compromise with their national minorities".
"If, however, the bombers were Islamic extremists," it adds, " then current European reservations to America's response are untenable."
The Polish Gazeta Wyborcza makes a direct link with the 11 September attacks, which were "intended to kill, and the more innocent victims the better".
"Did al Qaeda want to punish Spain for its alliance with the United States and its part in the Iraq war?" it wonders.
In the Czech Republic, Pravo warns that, in central Europe too, "every tram, train or underground journey could one day become a deadly adventure, as is already the case in Moscow, Jerusalem - or Madrid".
Still further east, the Russian newspapers are also preoccupied with the bombings.
"Europe has been confronted with the "most heinous crime in its entire post-war history," Nezavisimaya Gazeta cries.
"Europe will never again be the same as it was before 11 March," Izvestiya says.
"In blowing up the Spanish stations, the terrorists dispelled her illusions, made her less naive, less good-natured. One would like to believe they have made her more protected."
But the paper also hopes that the events have made Europe "less supercilious."
"What are European politicians, MPs, rights activists and journalists going to do after 11 March?," it asks.
"Will they, for instance, continue to demand that Moscow sit down at the negotiating table with those who organized the invasion of Dagestan and the explosions in Russian towns?"
"Or will they finally try to put themselves in our place?"
The European press review is compiled by BBC Monitoring from internet editions of the main European newspapers and some early printed editions.