The Basque terrorist group Eta has declared a permanent ceasefire, calling it a step towards ending its fight for independence.
But a statement in the pro-independence newspaper Gara did not mention Eta giving up its weapons - a key Spanish government demand.
Eta declared a ceasefire in September but gave no details about how long it would last.
The new statement specifies it is a "permanent and general ceasefire which will be verifiable by the international community". It added: "This is Eta's firm commitment towards a process to achieve a lasting resolution and towards an end to the armed confrontation."
Eta declared what it called a permanent ceasefire in 2006 but that truce lasted just nine months as talks with the government failed. Eta resorted to violence in December 2006 with a huge car bombing that killed two people at Madrid's Barajas airport.
The group's last deadly attack in Spain was a July 2009 car bomb that killed two policemen on Majorca.
The group is considered a terrorist organisation by Spain, the European Union and the United States, and it has killed more than 825 people since the late 1960s.
The Spanish government rejected the ceasefire announcement and demanded that ETA dissolve.
In Spain, speculation has been rife for weeks that Eta would issue a new statement, but the government has urged caution, saying the group has raised hopes before only to dash them.
Interior minister Alfredo Perez Rubalcaba said current and previous governments have repeatedly said all they want to hear from ETA is that it is disarming and giving up.