Spain has blamed a Saturday-morning bomb explosion at Barajas International Airport—the country's busiest—on Basque separatist group ETA. The blast occurred in a stolen van at 9 a.m. local time, damaging a parking lot and the airport's Terminal 4. No injuries have been reported, but two people are reported missing. About an hour before the explosion three anonymous calls were made to authorities warning of the event. After a few hours, air traffic resumed at Terminal 4. Flights at the airport's other three terminals were not interrupted.