Zaragoza airport in northern Spain was evacuated today after a warning of an attack in the name of the Basque group Eta, an airport spokeswoman said.
"The terminal has been evacuated and security checks are going on," she said.
The Basque road assistance organisation DYA confirmed it had received a warning call and had alerted police.
"At 9.06 am we received a call in the name of Eta saying a grenade launcher was in place and would go off between 10.00 am and 12.00 am," a spokesman said.
The warning applied to both the military and civil airports in Zaragoza, she added.
Today is a national holiday in Spain to celebrate both the Spanish nationality and the patron saint of Zaragoza, the Virgin of the Pilar.
It was marked by a military parade in Madrid, attended by King Juan Carlos and some of the Latin American heads of state due to attend a summit in Salamanca on Friday.
Eta has attacked Zaragoza before. It exploded a rocket grenade at the airport in June and damaged an electricity station with a small bomb in September.