Police officers from across Spain are protesting the government austerity measures affecting them, including frozen pensions and the elimination of their Christmas bonus.
More than 5,000 people paraded Saturday to the Interior Ministry building in Madrid, blowing whistles and shouting slogans.
Jose Maria Benito, a spokesman for Spain's Unified Police Union, said "we are here to tell the government that security has to be its priority."
Benito said police were worried that budget cuts meant that working conditions were more precarious, that law enforcement equipment was not adequate and that the 15,000 officers who had left the force were not being replaced.
He said "in socially convulsive times, we need an adequate police response."