About 1,000 Spanish youths have clashed with police during the night on the edge of the capital Madrid.
By Pascale Harter
BBC News, Spain
The youths said they wanted to take on criminal gangs of Latin American immigrants who they complained were dominating their neighbourhood.
Three people were hurt and seven held in the clashes in the Alcorcon suburb.
Police fired tear gas at the rioters, who wore balaclavas or scarves to hide their faces and pelted them with bottles and coins.
Some armed with baseball bats and knives shouted: "Let's go and get those Dominicans."
The riot is linked to an incident in the same neighbourhood on Saturday night in which a young Spaniard fought with a Dominican resident in what locals say was a clash between rival gangs.
A gang of mainly Latin American immigrants, calling themselves the Latin Kings, is active in Alcorcon.
But many Spanish locals said that despite the slogans, this was not a race riot but the result of delinquency in a neighbourhood with high unemployment, which they say is neglected by the authorities.
Meanwhile Latin American immigrants in the area told reporters they feared they would be the target of more violence in the coming days.