Police make dozens of arrests and seize knives and drugs from anarchists in Guy Fawkes masks running amok in Trafalgar Square demo

Thousands of supporters of Anonymous, the anarchic hacking group, are in Central London, clad in masks inspired by the V for Vendetta film (pictured top right). The annual protest (main), starting at Trafalgar Square, is one of many held worldwide on November 5 against government cuts, corruption, surveillance and a flurry of other causes. More than 2,000 police, the vast majority dressed in riot gear, are marking a tight perimeter around the protesters who they fear may turn to rioting and looting.
Police have already made arrests as the protest moves through the capital (below right).