In July 1997, the armed Basque separatist group, ETA, kidnapped a young local councillor called Miguel Blanco and threatened to kill him within 48 hours.
The ultimatum sparked nationwide protests against ETA on a scale never previously seen in Spain.
Witness speaks to former Spanish Interior Ministry official, Gustavo de Aristegui.
PHOTO: Miguel Angel Blanco's sister, Maria del Mar, in front of a mural of her brother. (Getty Images)