10 March 1986,
A massive, noisy power outage against NATO in Hego Euskal Herria. On the tenth day, for ten minutes, it was called from 10 in the evening to 10:10. The initiative consisted of throwing nipples and rockets, touching bells, organizing pots and shuffling public lighting in some localities. There were no notable incidents, except in Oñati, in which, when the street lighting of the town was shut down, the Civil Guard barracks were unlit. When the guards were angry, they arrested a person. It was the eve of the NATO referendum.
Source:
Sabino Ormazabal, Bidea Objective Group, 500 non-violent actions, another way to tell the story (Manu Robles Arangiz Foundation).