Olympic Stadium and Olympic Park in Stratford, London
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London 2012: High alert as thousands to fly to Games

The UK's armed forces will take formal control of British airspace from Saturday as part of the security preparations for the 2012 London Olympics.

The measures come at a time when half a million additional people are expected to fly in and out of the south east of England.

Nigel Cassidy reports from the skies above the Olympic site.

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