MADRID (AP) — The Basque separatist group ETA says it has given up its entire arsenal of weapons and explosives to civil society groups – but warns the disarmament process isn’t formally complete.

“After giving up all its weaponry (arms and explosives) to Basque civil society representatives, it is now a disarmed organization,” the militant group said in a letter published by the BBC on its website.

The letter, dated Friday and signed with the ETA’s seal, is the group’s first public communique in more than five years, since it gave up the violence it waged to achieve an independent Basque state in southern France and northern Spain.

A group of activists self-appointed as “peace artisans” had already announced a disarmament strategy in southwestern France but ETA had not confirmed it directly.

Two of the mediators told The Associated Press they considered ETA’s statement legitimate. Both spoke anonymously given the sensitivity of the issue.

Spain and France consider the ETA to have been defeated, and therefore refuse to engage in the disarmament process. They demand that the ETA disband permanently.

In the letter, the ETA accuses both governments of being “stubborn” and persisting in a “winners and losers scheme.”

It also warns that the disarmament could still be derailed.

“We want to warn that still the process can be attacked by the enemies of peace,” ETA says, calling Saturday “disarmament day.”

“The only real guarantee to succeed are the thousands of people gathering tomorrow in Bayonne supporting the disarmament,” the group adds, referring to the southwestern French town where thousands of pro-Basque independence supporters are expected to take part in a demonstration to cap the disarmament.

Experts view the disarmament as symbolic, saying ETA’s arsenal had already been diminished, with much of it obsolete.

Earlier on Thursday, the Basque regional parliament also called for a disarmament to be “unilateral, complete, definitive and verified.”

ETA killed 829 people and wounded many others over 43 years of armed struggle.