Dozens of people have been injured when masked protesters clashed with police outside El Salvador's main cathedral.
The protesters burst into the cathedral after an anti-war demonstration. Opposition parties have opposed the deployment of troops in Iraq and the firing of social security workers in a bitter labour dispute.
Police fired rubber bullets and tear gas at demonstrators gathered outside the cathedral and protesters threw rocks at the security forces.
Red Cross workers said at least 20 of those injured were taken to hospital for treatment, and police said they arrested 15 demonstrators.
The protesters demanded that the country's new government, set to take office in June, immediately pull El Salvador's troops out of Iraq, following the lead of Spain's new Prime Minister Jose Luis Rodriguez Zapatero.
But El Salvador's conservative president-elect, Mr Tony Saca, has insisted he will keep the troops in Iraq until their scheduled return in August; he has not said if they will be replaced.
The cathedral in central San Salvador was the scene of several bloody clashes during the Central American nation's civil war more than 20 years ago.