A King's College London building was evacuated after masked anti-fascist protesters stormed an event featuring a controversial 'alt right' speaker.

Hundreds of students had turned out to listen to the speaker Carl Benjamin, who goes by the name of 'Sargon of Akkad' online, in a talk hosted by the KCL Libertarian Society.

Dramatic video footage shows the moment a group of masked men enter the lecture theatre waving an Antifa flag.

Demonstrators are said to have forced their way into a building before setting off its fire alarm and smoke bombs.

Mr Benjamin is a self-described 'classical liberal' Vlogger, known for his supposedly 'anti-progressive' views.

He has been described by various outlets as a member of the 'alt right' movement.

Antifa is a self-styled left wing anti-fascist group known for engaging in militant protest tactics.

A spokesman for the KCL Libertarian Society told the Standard: "We will continue to pursue our goal of resisting any threats to freedom of speech.

"By continuing to plan the range of events and campaigns we have in store, in order to encourage productive dialogue on a wide range of topics.

"The event has now been cancelled and evacuated after threats to the moderator. Speech, no matter how controversial, should never be met with violence."

The Met Police confirmed they were called to the university, in Westminster, just before 7pm on Monday night. They told the Standard the group had been dispersed by the time they arrived.

The Standard approached KCL and Antifa for comment.