Thousands of people lined the streets of the Spanish cities of Madrid and Bilbao on Saturday (January 13), in a demonstration against ETA. The demonstrators carried banners calling for peace and liberty, and in memory of the two Ecuadorian immigrants who were killed by ETA bomb at Madrid airport late December. Hundreds of thousands of people marched, mostly in silence, for peace and an end to Basque separatist violence on Saturday (January 13) in demonstrations in Madrid, Bilbao and other Spanish cities. Marchers carried banners with various slogans including, 'For peace - against terrorism', 'We are all victims of ETA' and 'Peace and Dialogue - We Demand that ETA Ceases Violence'. The protests, which have caused political bickering in Spain about who should take part and under which slogans, came two weeks after the armed Basque group ETA shattered its nine-month permanent ceasefire with a massive car bomb at Madrid's Barajas airport, leaving two people dead. The marches finally got under way under the slogan, 'For Peace, Life and Liberty and Against Terrorism'. The squabbling meant that the main opposition, Popular Party, was absent from the Madrid march, the first time a major party has been absent from an anti-ETA demonstration since democracy returned to Spain in the 1970s. This prompted other slogans such as 'Absences help ETA and Where is Gallardon?' -- a reference to the PP mayor of Madrid Alberto Ruiz Gallardon. Meanwhile, Batasuna, the banned political wing of ETA, refused to join the Bilbao march because the slogan of the protest includes the phrase, 'We Demand ETA Ends Violence'. The Bilbao town hall estimated that 80,000 had joined the protest in the Basque city. The PP, led by Mariano Rajoy, had said it would only join the Madrid march if its slogan contained the word 'liberty'. When this was inserted by the organisers, the PP decided it would not join anyway and demanded both marches be called off, accusing the government of having no realistic anti-terrorism policy. Earlier in the week, ETA said a ceasefire declared in March was intact but simultaneously claimed responsibility for the Barajas bomb and threatened further action. Since the blast, the government has broken off the peace process but has been under intense pressure from the PP to say what its policy on the Basque region will now be. Socialist Prime Minister Jose Luis Rodriguez Zapatero will appear in congress on Monday (January 15) to discuss the issue but did not attend the Madrid march which was called by trades unions and a group representing Ecuadorian immigrants, as both victims of the latest bomb were from that country. Another group, the Association of Victims against Terrorism, which has organised large anti-ETA marches in the past supported by the Popular Party, was also boycotting the protest because it says it was an act supporting negotiation with terrorists. ETA has carried out a near four-decade violent campaign for a separate homeland, encompassing the regions straddling the western Franco-Spanish border, killing over 800 people.