Authorities in Spain say a bomb has exploded in a train station in the Basque region of the country. No injuries are reported.
There has been no claim of responsibility for the early morning blast Monday.
The explosion came one day after police detained 18 suspected members of an outlawed Basque youth group that the Spanish Supreme Court last month ruled is a terrorist organization with alleged links to ETA.
ETA is blamed for more than 800 deaths since 1968, when it launched an armed campaign for creation of an independent Basque state in northern Spain and southwestern France.
Some information for this report was provided by AP and Reuters.