A new mural by elusive street artist Banksy has appeared on the side of the Royal Courts of Justice building in central London.

It depicts a judge in a traditional wig and black robe hitting a protester lying on the ground, with blood splattering their placard. While the mural does not reference a particular cause or incident, its appearance comes two days after almost 900 people were arrested at a London protest against the ban on Palestine Action. The artwork was quickly covered up by large sheets of plastic and metal barriers. Court officials told the BBC the work would be removed. The Metropolitan police said it had received a report of criminal damage and that enquiries would continue. A spokesperson for HM Courts and Tribunals said that the Royal Courts of Justice was a listed building and that it was “obliged to maintain its original character”. The spot Banksy chose was on an external wall of the Queen’s Building, part of the Royal Courts of Justice complex, on the usually quiet Carey Street. On Monday it was busy with onlookers taking pictures of the recently hidden patch of wall.

One of two security officers outside the building said they did not know how much longer they would be required to stand guard, adding, “At least it’s not raining.”