Car Bomb at Madrid's Airport!

MADRID, Spain (CNN) -- Spain has blamed a powerful bomb explosion Saturday at the country's busiest airport on Basque separatist group ETA, declaring it a violation of a nine-month cease-fire.

The bomb at Barajas International Airport is "absolutely incompatible with the permanent cease-fire that ETA declared nine months ago," Spanish Prime Minister Jose Luis Rodriguez Zapatero said during a nationally televised news conference.

He ordered the government to halt any peace efforts, but he declined to say that the attack "breaks the cease-fire," which was the way Interior Minister Alfredo Perez Rubalcaba described it to reporters a few hours earlier.