Eta said Ignacio Uria Mendizabal was "executed"
The Basque militant group Eta has claimed responsibility for shooting dead a businessman who was involved in building a high-speed railway in Spain.
Eta described the killing of Ignacio Uria Mendizabal, 71, as "an execution".
And it warned that anyone else involved in the construction of the rail link between the Basque region and Madrid "will be an Eta target".
Eta is blamed for the deaths of more than 820 people in its 40-year campaign for an independent Basque nation.
Mr Uria was its latest victim, shot in the head outside a restaurant in Azpeitia, in the Basque region of northern Spain, in December.
A few days later, thousands of people marched through the streets of Azpeitia in protest at the killing.
In a statement to the Basque newspaper Gara, Eta also took responsibility for two bombings in November and December, neither of which caused casualties.
Work 'to go on'
Eta opposes the high-speed train link connecting the Basque cities of Vitoria, San Sebastian and Bilbao to the Spanish capital Madrid, saying it is not in the interests of the Basque people.
Thousands of people protested against the killing of Mr Uria
"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.
"While the destruction brought about by this big project continues, decided by decree and without public debate, the chosen officials and their holdings will be an Eta target."
After the killing of Mr Uria, Spanish Prime Minister Jose Luis Rodriguez Zapatero vowed work on the train link would continue, though it has been reported that dozens of extra bodyguards have had to be hired to protect those involved.