Thousands of masked anarchist protesters march through London

Anarchist protesters wearing Guido Fawkes disguises brought their anti-capitalist message to the heart of London for the annual Million Mask March.

Thousands of people, including those sporting the famous stylised vizard popularised in the cult film V For Vendetta, chanted pro-civil liberty and anti-establishment slogans as Westminster ground to a virtual halt.

Police maintained a heavy presence outside key locations such as Downing Street, with Scotland Yard enforcing restrictions over the scale and location of the protest following ugly scenes in previous years when bloodied activists clashed with officers.

The event, organised by the notorious hacking collective Anonymous, is held on November 5 every year.

Police imposed conditions on the march, limiting it to a three-hour period between 6pm and 9pm on a prescribed route between Trafalgar Square and Whitehall.

A post on the event's Facebook page ahead of the march, which warned activists that "police are not your friends", read: "We have seen the abuses and malpractice of this government, and governments before it.

"We have seen the encroaching destruction of many civil liberties we hold dear, we have seen the pushes to make the internet yet another part of the surveillance state.

"We have seen the Government's disregard for migrants, for the poor, the elderly and the disabled, we have seen the capital, profit and greed of the few put before the wellbeing of the many and we say enough is enough."

It finishes: "The Government and the 1% have played their hand. Now it's time to play ours. Expect us."