Around 3.5 tonnes of arms, explosives and other materiel have been found in eight arms dumps identified by ETA, French Prime Minister Bernard Cazeneuve said Saturday, following the Basque separatist group's vow to disarm.
"The French government welcomes this operation, carried out calmly and without violence," Cazeneuve said in a statement.
"It's a decisive step towards the end of Basque separatist terrorism."
ETA said in 2011 that it was abandoning its armed struggle for independence in the Basque region straddling the Spanish-French border and announced its "total disarmament" on Saturday.
The group provided France with a list of locations for its arms caches -- a move welcomed by Paris but deemed insufficient by Spain, which called on ETA to disband completely.
"The dangerous products will be destroyed," Cazeneuve said.
"Arms and equipment will be evaluated by justice authorities who will work, as always, in close collaboration with Spanish justice authorities to verify if the material gathered can help to resolve cases underway."
He added: "Whether the disarmament is, effectively, total will also be established."
The French premier said he hoped ETA's vow to disarm would mark "the end of five decades of violence" and herald "an era of lasting peace which the Basque Country should never have gone without",