Suspected ETA separatists shot and killed a businessman in Spain's northern Basque region on Wednesday, in the first attack linked to the group since the arrest of its military chief last month.

"Everything seems to point to ETA," an anti-terrorist source said.

Police said the man was gunned down at around 1 pm (1200 GMT) in the car park of a restaurant in the Basque town of Azpeitia. Emergency services said he died about an hour later.

Spanish news media said the man was shot once in the head and once in the chest by two assailants who then fled.

The Basque news agency Vasco Press identified the victim as Ignacio Uria Mendizabal, 71, the head of a company, Altuna y Uria, that is involved in the construction of a high-speed railway in the region -- a project opposed by ETA.

This year ETA has carried out three bomb attacks against companies working on the project, but without causing casualties.

If confirmed as the work of ETA, the shooting would be its first such attack since the November 17 arrest in France of the suspected military chief of the organisation, Garikoitz Aspiazu, alias Txeroki.

It would also be the first fatal shooting since a municipal councillor, Isaias Carrasco, was gunned down in the Basque Country two days before March 9, 2007 general elections in Spain.

ETA is blamed for the deaths of 824 people in its 40-year campaign for an independent Basque homeland.

It called off a 15-month-old ceasefire in June last year, saying it had grown tired of a lack of concessions on the part of the Socialist government of Prime Minister Jose Luis Rodriguez Zapatero in their tentative peace talks.

That truce had effectively ended when ETA bombed a Madrid airport car park in December 2006, killing two Ecuadorean men who were sleeping in their cars.

A judge in Spain last week charged Txeroki with terrorist offences in connection with that attack.

Since officially calling off its ceasefire, the group has been responsible for five other deaths: Carrasco, three Spanish security officers and one soldier.

The high-speed railway will link Bilbao, the Basque region's seaside financial centre, with its regional capital Vitoria and the city of San Sebastian near the French border.

ETA in the past has taken aim at major construction projects seen as harmful to the environment as a means of gaining support.