Five small bombs have exploded on highways around Madrid in Spain.
The Basque separatist group ETA had been reported as warning of attacks shortly beforehand.
It appears that the blasts caused no injuries.
Earlier, ETA was said to have threatened to launch a grenade attack on Santander airport in northern Spain.
Police evacuated the airport this morning after the Gara newspaper said a caller claiming to be from ETA warned of an attack on the airport between 1100 and 1300 GMT.
In the event, no attack was carried out.
ETA, which is seeking the creation of an independent state for the Basque people, has not killed anyone since May 2003.
However, it has frequently set off non-fatal bombs.
