A state memorial service has taken place in Madrid for the 190 people confirmed killed by the commuter train bombings on 11 March.
Many world dignitaries attended the sombre service
King Juan Carlos and the rest of the Spanish royal family led mourners at the service at Almudena Cathedral.
Important meetings are being held on the sidelines of ceremony, as world leaders meet the Socialist prime minister-elect Jose Luis Zapatero.
He met UK Prime Minister Tony Blair first, in "warm and friendly" talks.
Among other dignitaries attending were German Chancellor Gerhard Schroeder, French President Jacques Chirac, US Secretary of State Colin Powell and the UK's Prince Charles.
It is the first state memorial service for people outside the royal family in the history of Spain's new democracy, restored after dictator General Francisco Franco died in 1975.
Security was tightened across the city, with extra officers at Madrid's two airports,
roads leading into the city and along the route leading motorcades to the cathedral.
A sombre king greeted world leaders clad in black as they arrived for the service.
Around 1,500 people filled the cathedral, where behind the altar hung a white sheet carrying a black ribbon of mourning.
Many members of the congregation were unable to find places in the cathedral and had to attend in a square outside.
Giant TV screens carrying the ceremony live
were set up in the courtyard outside the
cathedral, in a garden of the royal palace and in one of Madrid's largest plazas, Puerta del Sol.
Madrid Archbishop Antonio Rouco Varela sought to comfort the mourners in his sermon.
"Great pain has filled your lives and those of your
families since that black day in which brutal terrorist
violence, planned and executed with unspeakable cruelty,
ended the lives of your most beloved," he said.
Atocha station, where many of the victims died
Spanish TV broadcast an on-screen list of all the dead, as the service drew to a close in the background.
And afterwards members of the Spanish royal family - many of whom wept during the service - shook hands and embraced relatives of those who had died in the bombings.
But there was anger as well as sadness among the mourners. One man vented his feelings at outgoing Prime Minister Jose Maria Aznar, who is accused by many of provoking the attacks by sending troops into Iraq.
"Mr Aznar, I hold you responsible
for the death of my daughter," he said.
The devastating terror attacks in Madrid saw 10 bombs explode on four trains in three stations during the busy morning rush hour.
The number of deaths was recently revised down from 202 to 190, although there are thought to be human remains yet to be identified.
Mr Zapatero, who was elected immediately after the attacks, has promised to withdraw Spain's more than 1,000 peacekeepers in Iraq unless the UN is given a strong mandate before the formal transfer of political power on 1 July.
The BBC's William Horsley says Mr Blair will have tried to persuade Mr Zapatero that his concerns in Iraq can be met and that Spain should remain part of the coalition effort to help bring long-term security there.
Zapatero is seeking a strong UN mandate in Iraq
Mr Aznar was a strong ally of the US and UK in the war and has strongly criticised the policy. Mr Blair had dinner with Mr Aznar on Tuesday night.
Mr Zapatero also held talks with Mr Powell, amid signs that the US was also seeking a resolution of the situation.
But the new Spanish leader held additional, separate meetings with Mr Chirac and Mr Schroeder, who both opposed the Iraq war.