Eta may be responding to the shock of last month's Madrid bombings

It follows comments by banned political party Batasuna - seen as the group's political wing - that Eta wanted talks with the new Spanish government.

"Eta has no place in a free nation," said Josu John Imaz of the moderate Basque Nationalist Party.

He was speaking as thousands of Basques celebrated their homeland day with rallies calling for more autonomy.

The BBC's Jonathan Charles in Spain says he was told by Batasuna official Fernando Barrena that Eta now believes it cannot achieve its aims by acts of terror.

Mr Barrena added that if the new Socialist government - due to take power in a week's time - agreed to negotiations, the goodwill would be reciprocated.

'Definitive decision'

Eta's possible change of heart follows the shock felt in Spain after last month's devastating Madrid railway bombings, an attack thought to have been carried out by Islamic extremists.

It has come under increasing pressure from the Spanish security forces, with more than 600 alleged supporters arrested in the past four years.

Batasuna leader Arnaldo Otegi said on Friday that he thought Eta was prepared to give up violence.

"Their latest statements, taking a clear position towards the new government of Spain to sit down and talk, point in that direction," he told Deia newspaper.

Some Spanish newspapers carried rumours that Eta was planning to announce a truce on Easter Sunday.

Moderate Basque parties have called on Eta to make a "definitive decision" on ending violence so "Basques can decide and have a future of peace and freedom".

"The Basque country asks [Eta] to open a democratic and peaceful process in a strategic and definitive way that allows the passing of the politically-driven historic conflict," said the Basque Nationalist Party in a joint statement with Eusko Alkartasuna.