Two grenades exploded Friday close to Zaragoza airport in northeastern Spain following warning calls by the Basque separatist group ETA, police said.
No one was injured, a police spokeswoman in Zaragoza said. She said the blasts occurred shortly after 12:30 p.m. (1030GMT). The grenades exploded about 300 meters (yards) from the airport, which had been cordoned off by police following warning calls in the name of the armed Basque group ETA.
A Spanish aviation department spokeswoman said the terminal had been evacuated as a precaution. She added that there were few people in the airport at the time of the blasts because the next scheduled flight was not until after 1 p.m.
Zaragoza, capital of the Aragon region, is located halfway between Madrid and Barcelona.
The blasts caused no damage to airport buildings.
Police later found three grenade launchers outside the airport complex, one with a grenade still in it.
The warning calls were made to the Basque daily newspaper Gara and the Basque region's traffic department, Gara said.
ETA, which is blamed for killing more than 800 people since 1968, frequently makes warning calls to both Gara and the Basque traffic department.
The group, whose initials stand for Basque Homeland and Freedom, wants independence for the three-province Basque region in northern Spain, along the border with France.
Most recently, it has been blamed for more than half a dozen non-lethal bomb blasts since Spanish Prime Minister Jose Luis Rodriguez Zapatero obtained parliamentary backing in mid-May for his proposal to start talks with the group if it renounces violence.
ETA's last fatal attack was a bombing that killed two police officers in May 2003.
The strike was defensive in nature and came in response to three attacks on the US military in February