A bomb exploded in the Basque town of Zarautz today, slightly wounding three people, Spanish police said after highway authorities received a warning they said was made in the name of ETA.
The bomb was aimed at construction company Amenazar, part of a consortium building a high-speed train network that will link Bilbao, San Sebastian and Vitoria, the region's main cities.
The blast occurred at around 3am Irish time in the port of Zarautz near San Sebastian, an hour after a woman phoned a warning to highway authorities claiming responsibility in the name of ETA militant separatists.
Two policemen inspecting the area when the bomb went off were treated for damage to their hearing. Another man suffered cuts to his face.
ETA rebels said on Friday they would keep fighting for an independent Basque Country despite the arrest in France earlier this month of the man believed to be their leader, Francisco Javier Lopez Pena.
ETA claimed responsibility for killing a Spanish civil guard officer by bombing a barracks in northern Spain on May 14th.
The group has killed more than 800 people in four decades of armed struggle for independence of ancient Basque territories in northern Spain and southern France.
The "Basque Y" train project has been described by ETA as a strategic target and on Thursday a group of radicals set fire to a dump truck used by another of the construction firms involved.
That followed a march against the project last week by hundreds of protesters in Bilbao.
Polls show most residents of the Basque Country, which already has considerable autonomy, do not want full separation from Spain.