London 2012: Olympics and Paralympics security test

A major exercise testing security and emergency services in the event of a terror attack during the Olympics and Paralympics is taking place.

About 2,500 personnel are taking part in the event in central London, which will test their response to a simulated attack on the London Underground.

Some of the activities at the disused Aldwych underground station in Surrey Street may be visible to the public.

The BBC's security correspondent Gordon Corera reports.

  • UK