London Olympic HQ built in secret for military

A source said last night: "It reflects the gravity of the threat."

Chinook helicopters have been in action over the capital for months ferrying special gear to the new East London HQ.

Underground bunkers will house even more crack troops.

The SAS will have a key role in massive security at the Olympics — using "black ops" BOATS to swoop via the Thames if terrorists attack.

A secret new riverside base being built for the Who Dares Wins heroes in East London will be home to a fleet of the high-powered rigid inflatables.

It means elite units can speed there "in seconds" using the network of waterways around the Olympic site that make it an island — with no fears about being held up in London's notorious traffic.