Thousands of people in Madrid have held a rally in protest at plans by the Catalan regional government to hold a referendum on independence.
Campaigners for Spanish unity filled Plaza de Cibeles calling for the Catalan regional president, Carles Puigdemont, to be sent to jail.
Similar demonstrations were held in other Spanish cities but the one in Madrid was the largest since the referendum was called earlier this year.
Spanish officials in Catalonia say they have sealed of more than half of the 2,315 polling stations in the region in order the halt the vote.
Spanish flags were flown by the thousands of protesters and some included the emblem used during the former dictatorship of General Francisco Franco.
President of the semi-autonomous region of Catalonia, Carles Puigdemont, has vowed to press ahead with the independence referendum despite government efforts to block it.