The violence late Saturday and early Sunday in three Basque cities — Durango, Renteria and Bilbao — caused no injuries although an apartment above one of the banks was evacuated as a precaution, the Basque regional interior department said.
A poll Sunday showed 58 percent of Basques believe their region's peace process, launched in March when ETA declared a cease-fire, has stagnated.
ETA and its political supporters accuse the Spanish government of dragging its feet, unfairly refusing to allow talks among Basque political parties — nationalist and mainstream — on the region's future and harassing pro-independence militants.
The government says resurgent pro-ETA street violence — which disappeared after ETA called the truce but now is back in force — must stop in order for the government to go ahead with promised talks with ETA on ending the nearly 40-year-old conflict that has claimed more than 800 lives.
The poll released Sunday by the Basque regional government said 35 percent of those questioned blamed the stalemate in the peace process on the refusal of ETA's outlawed political wing, Batasuna, to condemn violence.
Thirty-nine percent blame the government's refusal to move Basque prisoners from jails elsewhere in Spain to the Basque region itself — a long-standing ETA demand.
The survey was conducted from Sept. 26 to Oct. 11, before a gun heist in France that the government blamed on ETA and was widely criticized as yet another setback for prospects for peace.
The survey questioned 2,865 people and had a margin of error of 1.8 percentage points.