The Ministry of Defence says that similar missile defence systems have been deployed at all recent Olympic Games.
They will be in place by mid-July, along with Royal Navy helicopter carrier HMS Ocean (which will be moored in the River Thames), Royal Air Force Typhoon jets (which will be temporarily stationed at RAF Northolt), and Puma helicopters (at a Territorial Army centre in Ilford).
More top news
Model Rosie Nelson writes for ITV News, revealing why she is calling for MPs to pass a new law protecting models from becoming too skinny.
Amid calls for new laws to regulate the size of models, we look at how the face of fashion has changed over the past 60 years.
Amid calls for new laws to prevent models getting too thin, ITV News speaks to three women in the fashion industry to get their views.