More than two years after announcing a "definitive end to armed activity", the gestures by western Europe's last major violent separatist movement to officially disarm have been met with shrugs in Spain, which wants the group to disband without condition.
"The process of putting the arms under seal has begun and the ETA has committed itself to carry out the process down to the last weapon," read a statement published in the Basque newspaper Gara, dated February 24th.
The separatist group said the gesture would create a climate of "security" in the Basque Country and clear the way for a solution dealing with "all the consequences of the political conflict."
The ETA also called for an "urgent end of the violation of the rights of Basque political prisoners".
ETA was referring to the imprisonment of some 500 of its members in French and Spanish prisons. The group has long sought the transfer of these prisoners closer to home as a condition for negotiating its disbandment.
The prisoners issue has been a key sticking point on which Madrid has refused to budge.
Over recent months ETA members have tried to gain concessions from the Spanish government over prison conditions, outraging victims' families.
The communique confirms an earlier announcement by international ceasefire monitors that the group had begun giving up its arms.
The International Verification Commission on February 21st released a video of black-masked members of the group presenting to monitors revolvers, a rifle, bullets and explosives.
"The commission has verified that ETA has sealed and put beyond operational use a specified quantity of arms, ammunition and explosives," the body's spokesman, Ram Manikkalingam, told reporters in the Spanish Basque city of Bilbao.
"The commission is confident that this step is significant and credible. We believe that it will lead to the putting beyond operational use of all ETA's arms, ammunition and explosives," the Sri Lankan spokesman said.
Spain's conservative government seemed unmoved by the gesture by ETA while Spanish media derided the move as a "farce" and said the cache surrendered was ludicrously small.
Madrid does not recognise the five-member commission.
The ETA's own statement on its disarmament, the first of its kind, was similarly met with disdain.
The ruling Popular Party's number two Maria Dolores de Cospedal said the ETA should "stop the grandstanding and just dissolve once and for all".
ETA is blamed for the deaths of 829 people in a four-decade campaign of shootings and bombings for an independent Basque homeland in northern Spain and southwestern France.
It is classed as a terrorist group by both the United States and European Union.
The Spanish and French governments refuse to negotiate with ETA, which has been weakened over recent years by the arrests of its senior leaders in both countries.
Only about 30 of its active members are thought to be still at large.
Meanwhile, non-violent leftist Basque nationalist parties have gained political influence and increasing power through regional elections.
ETA was formed in 1959 during the dictatorship of General Francisco Franco by a group of Basque nationalist students.
It carried out its last known deadly attack in 2009, when it killed two police officers by placing a bomb under their car on the Spanish island of Majorca.