The Basque armed separatist group Eta today claimed responsibility for killing a 71-year-old businessman and threatened other people working on a high-speed rail project linking the region with Spain's capital.
In a statement to the Basque daily Gara, Eta described the December shooting of Ignacio Uria, whose firm was involved in construction of the high-speed train link in the Basque region, as "an execution".
"We want to send a clear warning to engineers, technicians, managers and leaders of companies which take part in the works or have anything to do with them that they should suspend their work," Eta said in the statement in Basque, quoted by Gara.
"While they go ahead with this destruction and this macro-project by decree and without public debate, the people cited and their properties will be an Eta target."
Eta says construction of the high-speed train link connecting the Basque cities of Vitoria, San Sebastian and Bilbao to the Spanish capital Madrid is not in the interests of Basque people.
Two gunmen shot Mr Uria in the head in the Basque town of Azpeitia before fleeing the scene in a stolen car.
After the killing, Spanish Prime Minister Jose Luis Rodriguez Zapatero promised the train link would continue.
Eta also took responsibility for two bombings in November and December - one which damaged the headquarters of the Basque region's local television station on New Year's Eve, and a second that exploded at a telephone mast.
Since 1968, Eta has killed more than 800 people in mainly bombings and shootings as part of its four decade campaign for an independent Basque homeland.
Polls show most Basques do not want an independent state.
Reuters