Drinkers in the Dial Arch had to be locked in tonight as a man armed with a knife tried to access the building.
Reports say there was no police response for 15-20 minutes after being called – as a video shows the man pacing outside with a knife.
Another person reported they had possibly the same individual making threats earlier in the day.
The man was eventually arrested by police.
The response time could be a result of changes to police in London as Basic Command Units have been introduced merging certain functions between boroughs. It has been criticised for slowing police response times – which were already under strain due to police cuts.