The BBC's Orla Guerin reports on the historic ceasefire announcement

The organisation said in an eight-point communique that it would cease all armed attacks from Friday.

But the communique also says the organisation will continue to resupply itself, will maintain its structures, and will defend itself if attacked.

ETA also reasserts its demand for independence for the Basque country, but suggests that it is willing to enter peace talks.

The BBC Southern Europe Correspondent, Orla Guerin, says the announcement is likely to be widely welcomed by the local community, which is weary of war.

The key question now, she says, is how Spain's ruling Popular Party will respond to the move.

Popular Party MP Jose Maria Robbes: "We don't trust them and we don't believe their word"

Popular Party MP Jose Maria Robbes said: "In the past we have seen many times that terrorists have said they were producing ceasefire or truce and then reassumed terrorist activities as soon as they could.

"So we don't trust them and we don't believe their word," he said.

Prime Minister Aznar: Rejects the ceasefire

The government has already dismissed any possible ceasefire as a ploy by ETA to buy time in order to regroup.

"I reject it expressly and formally," Prime Minister Jose Maria Aznar said on Monday during a visit to Colombia.

The central government has traditionally taken a strong stance and refused any negotiations with ETA until the separatist group lays down its arms and renounces violence.

The moderate nationalist government in the Basque country has called on ETA to give up violence but has not made this a condition for peace talks.

Northern Ireland example

There has been growing pressure from a broad range of interests in the Basque country - including nationalist parties, trade unions, social groups and peace campaigners - for a peace process like the one in Northern Ireland.

ETA has been blamed for more than 800 deaths in its 30-year fight for independence.

The organisation was still killing people as recently as three months ago. The latest casualty was a councillor from Spain's ruling Popular Party.

The prime minister himself avoided an assassination attempt by ETA in 1995.

Our correspondent says ETA is understood to have been heavily influenced by the Northern Ireland peace process. Its political wing has been schooled by Sinn Fein on strategy for negotiation.

Peace campaigners say an ETA ceasefire would be a breakthrough and one which could kick-start a Basque peace process.