UKIP has suspended three party members over their suspected involvement in a demonstration at a London bookshop that saw activists accuse a shop worker of being a paedophile, a “Nazi-bastard” and “corbynite scum”.

Police were called to Bookmarks in Bloomsbury after around a dozen demonstrators, including one wearing a Donald Trump mask, entered the shop just before it closed its doors at 6.45pm on Saturday. 

UKIP said party chairman Tony McIntyre had suspended Elizabeth Jones, Luke Nash-Jones and Martin Costello pending an investigation.

“It is understood that the three members were involved in an incident at the Bookmarks bookshop in London on Saturday,” the party said.

Video of the incident shows demonstrators abusing the lone staff member and throwing books onto the ground while chanting “Trump, Trump…. we love Trump”.

Bookmarks later wrote on Facebook that they had been targeted by “a dozen mask-wearing fascists”.

The Met told HuffPost UK on Monday that officers were to meet with the complainant, but no arrests had been made. 

Ealing Central and Acton MP Rupa Huq tweeted about the “utterly despicable” incident over the weekend, saying free speech and independent bookshops were “under threat”.

Michael Bradley, from Stand up to Racism, said the protest was a “sinister development that indicates the growing confidence of the far right who feel they can attack a bookshop in central London in broad daylight”.

He added: “Attacking a bookshop also exposes their claims to be defenders of free speech as hollow.” 

Writer Hussein Kesvani shared the video on Sunday, writing on Twitter that it was the “purest example of how toxic internet culture has seeped into real world street movements, that will at some point get people killed”.

The bookshop is planning on holding a “Solidarity Day” on Saturday, which almost 3,000 people have indicated they will attend, according to the shop’s Facebook page. 

Dozens of supporters have also posted messages of support.