Two bombs exploded in coastal towns in northern Spain injuring four people after a local paper received a warning in the name of the Basque separatist organisation ETA.
The explosions brought to seven the number of bombings in the north this month claimed by the political-military group ETA which seeks independence for the Basque country. A total of five people have been hurt, including those injured in the latest blasts.
One of the explosions, in the northwestern Galician town of Sanxenxo slightly injured two Spaniards and two Portuguese, according to local officials. The other was detonated in a controlled explosion in the nearby marina of Baiona, which police had evacuated.
A man who described himself as a member of ETA had warned of the imminent explosions in a telephone call to the separatist Basque newspaper Gara which is generally used by ETA to claim attacks. The secretary of the Basque Socialist Party Patxi Lopez said the point of the latest round of attacks was "only to show that (ETA) continues to exist."
The arrests in France and Spain and the banning of its political wing Batasuna have weakened ETA, though it continues to insist that it will target Spanish economic interests in its bid for independence. ETA violence has killed more than 800 people in 36 years.
Though it was initially accused of the March 11 train bombings in Madrid in which almost 200 people died it subsequently emerged those attacks were the work of Islamist radicals and ETA's last fatal attack was in May 2003, according to Channel News Asia.
Neither blast caused significant material damage, and no one was hurt in Baiona, regional officials told local media.
Four other small bombs have exploded at holiday resorts on Spain's northern coast this month.
ETA regularly stages summer bombing campaigns aimed at undermining tourism, a pillar of Spain's economy, although few tourists are scared away.
The newspaper Gara, which often receives warnings of ETA bombs, said on its Web site an anonymous caller claiming to represent ETA had warned of Saturday's blasts, told Reuters.