Thousands of people crowd a central square in the northern Basque city of Pamplona Friday March 12, 2004, during a demonstration to protest the numerous bomb attacks on trains in Madrid Thursday

Thousands of people crowd a central square in the northern Basque city of Pamplona Friday March 12, 2004, during a demonstration to protest the numerous bomb attacks on trains in Madrid Thursday that killed nealy 200 people and injured at least another 1,400. (AP Photo/Jon Dimis) MADRID, Spain -- More than a million demonstrators jammed the streets of Madrid on Friday night, huddling beneath umbrellas in a steady rain to protest the train bombings that killed 199 people in the country's worst terrorist attack. Millions more turned out in Barcelona, Seville, Valencia and other cities - including Spain's Canary Islands off the coast of West Africa. Spanish officials initially blamed the Basque separatist group ETA for the stunningly well-coordinated series of 10 explosions Thursday during Madrid's rush hour. Later, they said they were studying a claim of responsibility by a shadowy group in the name of al-Qaida. A caller claiming to represent ETA telephoned the pro-Basque daily newspaper Gara and said the separatist group "has no responsibility whatsoever" for the attacks, the paper told The Associated Press. ETA often issues statements through the Basque-language paper. Arnaldo Otegi, a top Basque politician, also denied ETA was involved and accused Prime Minister Jose Maria Aznar's outgoing government of "lying deliberately" about the bombing to seek political advantage in the elections.