Spain's outgoing prime minister on Wednesday defended the initial focus on Basque separatists as suspects in the Madrid (searchtrain bombings and accused his political foes of exploiting the crisis.

Prime Minister Jose Maria Aznar (searchsaid in an opinion article published in The Asian Wall Street Journal that his government was honest with Spaniards from the outset.

"In the hours that followed the attacks, our investigation focused on one obvious suspect, the Basque terrorist group ETA (search)," Aznar wrote. "It was a reasonable inference to make and those who say otherwise are either being naive or dishonest."

The worst terror attack in Spain's history killed 190 people and injured 1,800 on March 11, and Spain was quick to direct its blame on ETA, the Basque group that has killed hundreds of people through the years in its separatist campaign.

Aznar's conservative party had been favored to win elections that took place just three days after the bombing.

But his party lost as public opinion turned in favor of the opposition Socialists amid reports that the attacks might have been carried out by Islamic terrorists who wanted revenge on Spain for backing the United States in the Iraq war.

The Spanish opposition accused the government of a coverup. Aznar called that was a politically motivated lie, creating a "wildfire of innuendo" that "spread rapidly among many people who were justifiably indignant after the attacks."

But Aznar noted that as soon as authorities found an Arabic-language tape and several detonators in a vehicle the public was informed that a new line of investigation was being pursued.

"Those who twisted the facts in this way cannot feel very proud today," Aznar wrote. "Instead of backing the government during the worst crisis in Spain's recent history, our opponents declared that truth and transparency were on their side."