Deadly surface-to-air missile launchers have been put in place in six
strategic sites - in four parks and open spaces and on top of two
residential tower blocks - to protect the Games from the threat of airborne
attacks.

It comes as military chiefs warned they will use lethal measures to enforce a
30-mile no-fly zone around the Olympic Stadium - with Typhoon jets and Puma
helicopters patrolling the skies.

The installation of heavy-duty air defences around London marks the biggest
peacetime security operation the country has ever seen.