At least 53 people have been arrested at the Million Mask March in London, where thousands of people flooded the streets.
The demonstration, which takes place at locations around the world on 5 November each year, is organised by the hacking collective Anonymous and sees people wearing Guy Fawkes masks take to the streets to protest capitalism, corruption and internet surveillance, among other things.
The group marched from Trafalgar Square to Downing Street, carrying banners and flares, with several people in the crowd setting off fireworks along the route.
There was a heavier police presence than in previous years on the three-hour march – with both authorities and demonstrators appearing to anticipate clashes.
Marchers were warned early on during the event that the authorities might use kettling, while a post on a Facebook group linked to the event said: "the police are not your friends", the Evening Standard reported.
Meanwhile, the police had warned prior to the demonstration that some people were expected to come along simply to cause trouble, "intent on criminality".
Given the majority of people on the march wore masks, police also warned protesters it was an offence to refuse to comply with police requests to remove facial coverings, although it was not clear if any of the arrests were a result of this.