Security expert Will Geddes says that the public shouldn't be too alarmed by the fact that a known terror suspect has entered the Olympic Park.
Instead, he says we should take comfort from the fact that the security services were able to track his movements.
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The high of 35C was recorded on a Bakerloo line train between Piccadilly Circus and Oxford Circus at 2pm.
Weather forecasters say temperatures could reach 35C, beating the previous record of 34.6C in the scorching summer of 1976.
After years of political manoeuvring over the future expansion of Heathrow Airport, there has been an important development this lunchtime.