Basque separatist group ETA plans to announce it is giving up its weapons, Spanish newspaper El Pais reported.
The group is set to reveal the locations of its weapons caches to Spanish authorities later on Friday, the newspaper said.
From 1968 to 2010, ETA was engaged in a bloody campaign to carve out an independent Basque state from parts of northern Spain and southern France, leaving more than 800 people dead.
At the end of 2011, ETA announced the end of its armed struggle. The group has not committed any attacks since, but disarmament has not proceeded.