The Zaragoza airport in northern Spain was evacuated Wednesday after it received threats made in the name of the Basque separatist group ETA.
Officials say they received word that a rocket launcher had been set up to carry out an attack during a two-hour time frame.
Police found no explosives or any evidence an attack was planned. The airport has been reopened.
ETA fired a rocket at the Zaragoza airport in June, but no one was hurt.
ETA has been blamed for more than 800 deaths since the 1960s when it began its armed campaign for an independent Basque state in northern Spain and southwestern France.
Some information for this report provided by AP