At 7:30 a.m., residents in the elegant Salamanca area of Madrid woke up to a violent explosion. ``I thought our building was falling down,'' said Barbara Vega Munoz, who lives a few blocks away from the site of the bomb blast.
In the single most deadly attack against the police to date, five paramilitary civil guards were killed and four wounded on Friday as they returned from night duty at the Italian Embassy here. The bomb that destroyed their Land-Rover was in a parked car and was detonated by remote control.
Although no group has claimed responsibility for the attack, police said the method and target of the blast were characteristic of the Basque terrorist organization ETA (Basque Homeland and Liberty).
Since the return of democracy 10 years ago, major terrorist attacks have come at key moments in Spain's political life.
Last week's bomb blast came just days after the government called for early elections in June.
ETA has been implicated in terrorist attacks that occurred shortly after the Socialists took power in 1982, on the eve of Spain's signing of a treaty to join the European Community last December, and after government announcements this January of a March referendum on the nation's continued membership in NATO.
ETA has used terrorism in an effort to destablize democracy and bring about nationalist independence for the northern Basque region of Spain, but analysts say its chances of achieving these goals today are minimal.
Shortly after Friday's attack, demonstrators pressed against police cordons at the site of the blast, arms raised in the Fascist salute, shouting insults against the government and in support of the jailed Army officers who attempted a military coup in February 1981.
In recent months, the Basque terrorist organization has been curbed, and terrorism has fallen off in the Basque country. This is attributable in part to more effective police action and more collaboration from French authorities in pursuing ETA members in their traditional haven across the French border. Murders of ETA sympathizers by the mysterious GAL (Antiterrorist Liberation Group), which some claim is linked to Spanish police, have also thrown ETA into disarray.
Applying a carrot-and-stick approach, Spanish authorities have claimed some degree of success by offering ETA terrorists the chance to lay down their arms and reenter society. Dozens of ETA members have been trickling back into Spain.
But a small group of hard-core ETA military terrorists still has the logistical capacity to carry out well-planned actions and has clearly opted for the spectacular attacks in Madrid that draw the most attention. A government official who does not want to be identified said authorities were expecting a series of violent actions by the dangerous Commando Espana that operates in the capital.
ETA has built its fight around a five-point plan, some points of which could be negotiated -- such as a general amnesty and the role of the police in the Basque region.
In recent months there have been increasing rumors of possible negotiations. In the past, Interior Minister Jos'e Barriounuevo Pena has adamantly rejected the idea. ``With an armed organization, you negotiate on the arms. With a political organization, you negotiate politically,'' he said.