The owners of Britain’s largest socialist bookshop, Bookmarks, have said the store was attacked by far-right protesters wearing masks who wrecked displays and ripped up books and magazines.

Posting on Facebook and Twitter, Bookmarks said staff were closing the shop on Bloomsbury Street in central London on Saturday evening when about a dozen people descended on it.

A Met spokesman said: “Police were called at approximately 18:35hrs on Saturday, 4 August to reports of a protest inside a shop on Bloomsbury Street, WC1.

“No other offences were disclosed at the time. Police received a second call a short time later stating that the group had left the premises after causing some damage inside the shop. There were no injuries. An appointment has been made for officers to speak with the complainant. No arrests have been made.”

The campaign group Stand Up To Racism, speaking on behalf of Bookmarks, said some of the attackers carried placards reading “British Bolshevik Cult” and that one of those involved wore a Donald Trump mask.

A far-right protest against censorship of the conspiracy theory website Infowars took place in central London on Saturday at which protesters were seen with the same placards. Others wore “Make Britain Great Again” caps.

Bookmarks sells a range of books from politics to economics and from history to fiction. It is also the official bookseller for the Trades Union Congress.

Michael Bradley, from Stand up to Racism, said: “Luckily no one was hurt this time, but this is 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.

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

Bookmarks said no one was hurt during the incident: “We will not let this happen! Never Again!” it said.

The attack was condemned by the Labour MP Rupa Huq, who tweeted: