The government of Spain's Basque region warned ETA still has cells operating across the country.

Basque interior minister Javier Balza said ETA had "several operational cells in Euskadi (the Basques' name for their region) and, probably, also outside of Euskadi".

On Tuesday, the terrorist group carried out two bomb attacks in under 24 hours, pushing to 11 the total number of attacks carried out in 2006. Two police officers were slightly injured in the first attack on a business premise in the Basque Country.

Since Jose Luis Rodriguez Zapatero said last month that circumstances were propitious for "the beginning of the beginning of the end" to terrorism by ETA, the group has staged five attacks.

ETA has killed 817 people since it took up arms in 1968, when Spain was governed by the dictatorship of Francisco Franco, with the aim of carving out an independent Basque nation from portions of northern Spain and south-western France.

The terrorist group, however, has not committed any murders since May 2003, even though it has continued targeting businesses and government offices across Spain.

Balza said there "are expectations and we have gone many months without attacks that killed anyone," but he added that it was unacceptable for ETA to continue carrying out acts of violence.

The Basque Region, which enjoys a high degree of autonomy, is governed by moderate nationalists who seek some form of "sovereignty" but adamantly reject the use of violence to achieve that end.

"We're not on the right path and we should change immediately," Balza said, noting that ETA had an opportunity in recent months to "establish channels (of communication) with the (Spanish) state and in Euskadi, which months ago it did not have".

"All terrorists should end up in front of a judge," Balza said, adding that it would be necessary to "maintain the support, by way of the resolution made in (the Spanish) Parliament to seek the possibility of an end to the violence via dialogue."

Balza said there "exist the conditions, like never before, to try to end the terrorist violence" and "with a prudent effort progress can be made".

Hope for an end to ETA's 38-year campaign of terrorist violence has dominated the political debate in Spain in recent weeks, especially since Zapatero's comments 10 February.

Zapatero said his appraisal of the situation represented neither "optimism nor pessimism" but was rather based on facts, such as an absence of lethal ETA attacks since May 2003. He also cited "information the government has," which he said must be handled with discretion.

The government, however, said it has not had contacts with ETA and any dialogue would be conditioned on the Basque terrorist group laying down its arms, after which Parliament would be asked to authorize any talks.

ETA issued a statement last month addressing speculation about a possible truce and said "the solution to the conflict will not come through unilateral decisions".

The group called on all Basque actors "to take steps now without waiting for anyone. The time has come to make firm commitments and important decisions on the future of Euskal Herria (the Basque region), moving boldly from words to deeds".

ETA is an acronym for the Basque words meaning "Homeland and Freedom."

Some associations of victims of terrorism, meanwhile, have called on the government, with the support of the opposition conservative Popular Party (PP), to accept only an unconditional surrender by ETA.

The PP has accused Zapatero's government of giving up any hopes of "defeating" ETA.

Police unions have also expressed concern about the increase in the number of attacks being mounted by ETA.

Two unions representing members of the Basque regional police force said this week that the likelihood was rising of ETA "sooner or later" killing again.