A decade on, Spain remembers Tuesday as the day Al-Qaeda-inspired bombers ripped asunder four packed commuter trains, killing 191 people, as its security forces now grapple with new and emerging jihadist threats.
A policeman walks near one of the trains that was attacked at the Atocha train station in Madrid, March 11, 2004
The Spanish royal family led by King Juan Carlos, as well as Prime Minister Mariano Rajoy, will join a mass for victims in Madrid's Almudena Cathedral, a solemn ceremony for a nation still wary of extremist Islamists and "lone wolves" lured to their cause.
The shrapnel-filled bombs detonated at 7:40 am on March 11, 2004, in packed commuter trains headed to Madrid's main Atocha railway station, massacring 191 people and wounding about 2,000.
For many survivors, the physical and psychological scars of the deadliest terrorist attack in Spanish history run deep.
- 'Fear always with you' -
Antonio Gomez, a married 48-year-old bank computer designer with daughters now aged 10 and 15, was in a train at Atocha when a bomb detonated.
He was reading a newspaper that protected his face from the flying shards of shattered windows.
"But bits of glass embedded in the face of a little girl beside me," he recalled.
With a fellow passenger, Gomez said he managed to force open a door of the collapsed train, as people trampled over each other to escape onto the platform.
He called his pregnant wife on his cell phone.
"Just after telling her what happened and not to worry because I am all right, that is when the second bomb went off and the mobile was cut off," Gomez told AFP.
"The blast wave caught me and I fell to the platform, and the blow broke my left leg," he said.
"There were mutilated people, people thrown on the ground, people in a very bad state. I was one of the better off. It was Dantesque. I don't like to remember it."
These days Gomez switches the channel when he sees television reports of the attack.
"It is not good, but I avoid it. On the 11th I will probably go to the cinema or watch the children's station Disney Channel," Gomez said.
Even now, he rarely travels by train. "The fear is always with you."
Spanish courts eventually sentenced 18 people for the bomb attacks.
The seven chief suspects committed suicide on April 3, 2004, by blowing themselves up in an apartment near Madrid, also killing a policeman.
On the eve of the 10th anniversary commemorations, Spain's Interior Minister Jorge Fernandez Diaz said Islamist extremists were still a threat.
- 'We're in their sights' -
Al-Qaeda's leaders and its affiliates, including north African group Al-Qaeda in the Islamic Maghreb and armed Islamists fighting the regime of Syrian President Bashar al-Assad, refer frequently in their statements to "Al Andalus", in reference to Spain, he said.
"Clearly Spain forms part of the strategic objectives of global jihad. We are not the only ones but we are in their sights obviously," Fernandez Diaz said.
The Madrid train bombing also sparked off a bitter political dispute.
Immediately after the attacks, then prime minister Jose Maria Aznar's conservative government declared that the prime suspect was the armed Basque separatist group ETA.
The claim was viewed with deep suspicion, however, because the government faced a general election three days later and Aznar had been among the most fervent supporters of the US-led invasion of Iraq, despite popular opposition in Spain.
"Honestly, we have to say that it has not been possible to show any relation or link between ETA and those who were the material authors of the attack," Fernandez Diaz said.
Voters punished Aznar in the following elections, which were won by Socialist Jose Luis Rodriguez Zapatero, an opponent of the Iraq war.
Since the day of the bombings, 472 suspected Islamic extremists have been arrested in Spain, Fernandez Diaz said.
Some 1,800 Spanish police and counter-terrorist security forces, in addition to the intelligence service, now grapple with the threat of a new attack, the minister said.
The Spanish counter-terrorist service's alert level is at its second-highest category, signifying "a likely risk of attack", a level that has not changed in recent years, he said.