Some bystanders suffered slight injuries. At one stage police charged the rival groups as they spilled on to Waterloo Bridge, bringing traffic to a halt. The Underground and mainline stations were closed and some British Rail services were suspended. Lambeth North Tube station was also closed for 25 minutes.
Outside Waterloo, missiles, including bottles, were hurled as skinheads arrived to be greeted with Nazi salutes and flags with swastikas. British Transport Police said two of its officers were taken to St Thomas's Hospital, one with a glass wound to the face.
As the rival groups spread out along the South Bank, concertgoers and musicians from the Royal Festival Hall were caught in running lines of police trying to control the disturbance. A saloon car was smashed.
Trouble began when about 100 neo-Nazi supporters arrived at Waterloo in the late afternoon to travel by bus to a concert organised by the neo-fascist group Blood and Honour at an undisclosed venue in south-east London. The event, advertised in posters all over Europe, was due to feature the skinhead band Screwdriver.
Scuffles broke out between police and members of the Anti-Fascist Action Group. As some protesters chanted 'police protect Nazi scum', the neo-fascists were divided into groups of 20 and escorted out of the area.
While they waited for their buses the anti-fascists threw rocks, stones and bottles at them. As the police moved in with batons and riot shields, both sides jeered and spat on the officers.
Ray Candy, the duty manager at Waterloo, said the station had been closed to protect the public. 'There was no alternative,' he added.
Eamonn Kent, a spokesman for the Anti-Fascist Action Group, said it would do anything to stop the concert. 'We hope it will be done peacefully, but we are undaunted at the prospect of physical confrontation, and in the end, it may well be like the Battle of Waterloo.'
The last time Blood and Honour tried to stage such a high-profile event, at Camden Town Hall in 1989, the group discovered the plans and the booking, made in a false name, was cancelled.