Supporters of imprisoned far-right activist rally in London

Police in London have kept supporters of a far-right British activist away from counter-demonstrators while shoppers and tourists watched

LONDON -- Police in London kept supporters of far-right activist Tommy Robinson away from counter-demonstrators Saturday, as shoppers and tourists in one of the capital's main shopping districts gawked at the spectacle.

Singing "We want Tommy out" and waving flags, the pro-Robinson camp congregated outside the Oxford Circus subway station to demand his release from prison.

Police imposed strict conditions on their demonstration, as well as on a counter-demonstration organized by an anti-fascist pressure group, Stand Up To Racism.

The rival groups only were allowed to congregate in certain areas for set lengths of time. Officers and vans separated the two sides.

Authorities warned that violence would be dealt with "swiftly and robustly."

Robinson, 36, whose real name is Stephen Yaxley-Lennon, co-founded the anti-Islam English Defense League.

He received a nine-month prison sentence for contempt of court last month for posting live video on social media of criminal defendants accused of sexually abusing teenage girls.

Robinson claimed to have been exposing alleged "Muslim rape gangs" when he recorded the men outside a courthouse in violation of an order intended to ensure fair trials.