Huge traffic jams snarl central Madrid, as Spain's first general strike in more than a year kicks off with nine people slightly injured in demonstrations, including police officers.
(CNN) Madrid - Interior Ministry official Cristina Diaz said 58 people had been detained. The cause was not immediately clear.
Dozens of union members picketed outside the Agriculture Ministry before dawn, with dozens of riot police on hand. Picketers heckled and momentarily blocked a car trying to get into the ministry.
Spanish unions are protesting the new conservative government's labor reforms and austerity cuts.