12 April 1997,
Nine members of the anti-militarist group KEM-MOC boycotted the flag oath at the Mungia headquarters. Among them was José Antonio Ulloa, who made the Spanish military believe that they were going to swear the flag, and on the arrival of their turn they took off their clothes and showed a t-shirt with antimilitaristic message. Eight other women who left the audience did the same.
Source:
Aitor Zuberogoitia, seven KEM antimilitarists boycotted the flag oath in Mungia (Euskaldunon Egunkaria, 13 April 1997).