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).
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A list of results for London Mayor and the London Assembly
They said they wouldn't do it. But the Met Police couldn't resist the challenge set by their colleagues in Scotland.
The results of the first preference votes counted so far gives an early indication that Mr Khan is line to take power at City Hall.