The Basque separatist group ETA has been carrying out attacks in Spain since 1968. ETA, which the Spanish government believes is behind the recent deadly bombings in Madrid, has previously killed about 850 people during its fight for Basque independence.

Following is a chronology of some of the major attacks carried out by ETA.

1959: The Euskadi Ta Askatasuna (ETA) group, also known as the Basque Homeland and Freedom group, is founded during the dictatorship of General Francisco Franco to fight for Basque self-determination.

1968: ETA complete it's first planned attack, killing Meliton Manzanas, police chief in the Basque city San Sebastian.

1973: Franco's Prime Minister Luis Carrero Blanco is killed when his car drives over explosives planted by ETA in Madrid.

1980: Nearly 100 people are killed as ETA keeps up its attacks despite Spain's recent return to democracy.

Sept., 1985: An American tourist is killed while jogging in Madrid and 16 Civil Guards are wounded after ETA's first car bomb explodes.

July, 1986: Twelve Civil Guards are killed in Madrid and 50 injured. In April 2000, Repentant Basque separatist, Juan Manuel Soares, is sentenced to 1,401 years in jail for the killings.

June, 1987: Twenty-one shoppers are killed after a bomb explodes in a Barcelona supermarket. ETA apologizes for what it calls a "mistake."

April, 1995: Popular Party opposition leader Jose Maria Aznar who later becomes prime minister, survives a car comb thanks to the vehicle's armour plating.

August, 1995: Police foil ETA plot to kill King Juan Carlos.

July, 1997: Six million people protest the slaying of Basque town councillor Miguel Angel Blanco who is kidnapped and later killed by ETA.

Sept, 1998: ETA announces truce.

June, 1999: Government reportedly holds talks with ETA.

Nov. 28, 1999: ETA announces its ceasefire will end on December 3.

Feb. 22, 2000: Local Socialist politician Fernando Buesa and his bodyguard , Jorge Diez, are killed in a car bombing in Vitoria.

Sept. 15, 2000: The alleged top ETA leader, Ignacio Gracia Arregui, alias Inaki of Renteria, is arrested by French police.

Nov. 21, 2000: Close to one million people demonstrate after former Socialist health minister Ernest Lluch is killed in Barcelona.

Feb. 22, 2001: Two people are killed and four injured in San Sebastian after a car explodes. Hours later suspected ETA military chief is captured by French police in the French town of Anglet.

Nov. 6, 2001: Ninety-five people are injured after a car bomb explodes in Madrid. However, a senior civil servant who was believed to be the target of the attack escapes unharmed. Two suspected ETA members arrested.

Nov. 23, 2001: Ana Isabel Arostegi becomes the first female officer of the Basque police force to be killed by ETA. She and another officer are killed in Beasain, south of San Sebastian.

March 4, 2002: Police defuse bomb planted at Bilbao stock exchange reportedly by the Basque separatist group.

May 1, 2002: Seventeen people are treated for injuries after a car bomb explodes near Madrid's soccer stadium, hours before the European Champions League semi-final.

June 21, 2002: Seven are injured after three car bombs explode in a single day in towns of Fuengirola, Marbella and Zaragoza days before a two-day summit of EU leaders in Seville.

Dec. 4, 2003 - Ibon Fernandez Iradia, a suspected military commander of ETA, is arrested by French police. Iradia had escaped French custody almost a year before.

Feb 18, 2004 - ETA calls truce in Spanish region of Catalonia, less than a month before general elections.

Feb. 29, 2004: Spanish police intercept a van carrying more than 500 kg of explosives that ETA planned to set off in Madrid.

March 11, 2004: At least 173 people are killed after bombs explode at stations in Madrid during the mourning rush hour. Spanish ministers say the attack bears the hallmarks of ETA.