French police have found dozens of weapons and hundreds of kilograms of explosives at ETA arms dumps after the Basque separatist group abided by its promise to completely disarm on Saturday, the Paris prosecutor's office said.

"Police services went to the sites indicated (by ETA) and found, in metal containers and bags, dozens of handguns and rifles, thousands of rounds of ammunition, several hundred kilograms of explosives and components of explosives, several hundred detonators and timers," the prosecutor said in a statement.