The Basque separatist group ETA is warning it may launch new terrorist attacks, following its December 30 bombing at a Madrid airport that killed two people. From Paris, Lisa Bryant reports the blast has shattered Spanish hopes of eradicating Europe's last major terrorist group.

Female resident walks in front of graffiti from the Basque separatist group ETA in Alsasua, Spain, 9 Jan 2007

A statement published in a Basque newspaper and attributed to ETA suggests the group may strike again - in retaliation for what it calls government "attacks" in Spain's wealthy, northern Basque region.

But Tuesday, ETA had said it wanted to continue the peace process - while also taking responsibility for a Madrid airport blast that killed two people and injured roughly two dozen others. The bombing ended a nine-month-old "permanent" ceasefire declared by the separatist group last March. Experts suggest ETA was frustrated by the lack of advances in the peace process.

The United States and the European Union consider ETA a terrorist group. It is blamed for at least 800 deaths in its nearly four-decade campaign for an independent Basque country in northern Spain and part of southwestern France.

A spokesman for the group's political wing refused to comment on warnings ETA may launch further strikes. But Basque journalist and ETA expert Gorka Landaburu denounced the group's latest published statement.

Speaking by telephone from the Spanish Basque city of San Sebastian, Landaburu described ETA as completely irresponsible and unrealistic for both warning of future strikes and vowing to continue with the peace process.

Landaburu, a victim of an ETA attack, says the Madrid bombings surprised everyone, including Spain's prime minister, Jose Luis Rodriguez Zapatero.

Landaburu says Mr. Zapatero had invested a lot in a peace process launched with the separatists last year. It is too early to say whether it will cost him politically, Landaburu says, but the prime minister has taken a tough hit which has cost him points in recent polls. The Spanish government has declared the peace process is over. But Landaburu, for one, has his doubts.

Spain is used to terrorism, he says, and there are moments of hope and despair. But the country must continue with the process.