Leaders of the Basque separatist militant group ETA are asking members to vote on whether it should disband itself completely by the summer, according to a statement in newspaper Gara. ETA killed more than 850 people during a campaign to carve out an independent state in northern Spain and southwest France, Reuters said. The group is practically inactive since it handed over arms in April to end nearly half a century of separatist violence. With the help of mediators, it led French authorities to caches of weapons, explosives and ammunition. It had declared a ceasefire in 2011. Spanish Interior Minister Juan Ignacio Zoido tweeted on Thursday that statements were not enough, and called on ETA to dissolve completely and apologize to its victims.