Several people were injured in the clashes following the right-wing rally

Carlos Javier Palomino was one of several hundred activists trying to prevent an anti-immigration rally by a far-right party on Sunday.

Police detained a 24-year old man on suspicion of carrying out the stabbing in the Legazpi metro station.

The clashes follow recent reports of racially-motivated attacks in Spain.

The violence reportedly broke out when members of the small right-wing National Democracy party encountered a group of left-wing activists in the Legazpi station.

Mr Palomino was stabbed in the heart and treated at the scene but rescuers were unable to save him.

The man accused of stabbing him is believed to have been a participant in the anti-immigration rally.

Reports say at least eight other people, including a policeman, were injured in the violence, and emergency workers set up mobile hospitals to treat the injured.

Madrid is an open and integrated region where there is no room for racist, xenophobic or extremist expressions Alfredo Prada Madrid official

Hundreds of anti-racism protestors later brandished sticks and threw rocks and Molotov cocktails as they attempted to stop the rally from taking place.

The violence was condemned by Madrid's community justice spokesman, Alfredo Prada.

"Madrid is an open and integrated region where there is no room for racist, xenophobic or extremist expressions," Mr Prada told the Associated Press.

The clashes came weeks after a racially-motivated attack on a teenaged Ecuadorean girl provoked widespread indignation.

The number of immigrants in Spain has grown rapidly in recent years and they now makes up 10% of the population.

A recent poll for Publico newspaper found that most Spanish people are unhappy with the Socialist government's handling of immigration.