Spanish police found four bombs attached to the legs of an electricity pylon near the border with France today, after a warning yesterday from Basque separatist group ETA.
Explosives experts were deactivating the bombs on the high-tension tower in the northern region of Aragon, a national government representative in the region said.
Yesterday police blew up a bomb on another pylon near France, after a caller claiming to represent ETA warned they had put bombs on two electricity towers run by grid operator Red Electric.
ETA, who regularly target Spain's key tourist industry, appear to have adopted a new tactic of sabotaging the country's power infrastructure.
ETA has killed nearly 850 people since 1968 in a bombing and shooting campaign for an independent Basque state in northern Spain and southwestern France.
Spain, the United States and the European Union consider ETA a terrorist organisation.