Jenny Reeves (@Jennyflyer1) was one of the first to post a picture on Twitter.
And Transport for London sounded the all-clear after the "invasion" had been averted.
The filming of Doctor Who has finished at Westminster Bridge, the Daleks are in the process of being removed.
More top news
Eight fire engines and 60 firefighters are working to try and put out a large fire at a cafe in Fulham. One person has been injured.
A coffee shop in Fitzrovia is allowing customers to buy discounted hot drinks and pass them on to a homeless person
A man has been jailed for seven years for raping a woman after she fell asleep on a night bus in Hampstead