Tens of thousands of demonstrators took to the streets of the Spanish capital on Sunday to demand an end to the occupation of Iraq and the withdrawal of Spanish troops from the country.
The protest, organised by trade unions and social groups, comes a year after massive demonstrations in Madrid and Barcelona against the war in oil-rich Iraq.
Spanish Prime Minister Jose Maria Aznar, whose right-wing Popular Party is seeking re-election next month, was one of the staunchest supporters of the US-led invasion and subsequent occupation of Iraq.
Organisers said some 150,000 people took part in Sunday's march but local officials put the figure at around 9,000.
The protestors, who carried banners demanding "USA out" and "Popular Party go", found support from members of Spain's opposition Socialist Party (PSOE) and the Communist-led United Left coalition (IU).
IU leader Gaspar Llamazares appealed in comments to journalists for "the immediate return of Spanish troops" and the end "of an occupation that is totally illegitimate (and) which prompted a civil war in Iraq".
He urged Spaniards to reject government "lies" about Iraq's alleged weapons of mass destruction in the general election on March 14.
Similar demonstrations were due to take place in the eastern cities of Barcelona and Valencia.
Writer Rosa Regas and actor Juan Diego Botto read a statement at the end of the rally in Madrid calling for international troops to be withdrawn from Iraq and demanding the return of "sovereignty and self-determination to the Iraqi people".
Spain currently has almost 1,300 soldiers serving in Iraq. They were deployed by Aznar's government last August in the face of massive political and public opposition.