Emergency services, police and intelligence agencies will carry out the largest-ever rehearsal of a response to a terror attack across the city today. Exercise Strong Tower will involve more than 1,000 officers.
Rapid gunfire has been reported around the Strand, where police are in the midst of a major training exercise.
Earlier police said the exercise is to test the response by emergency services to the threat of a "marauding terrorist firearms attack in London."
The unlicensed events unfolded on Saturday night at Clapham Common and Tooting Bec Common.
A 37 year old man who was taken to hospital after getting into difficulty in a stretch of water near Maidenhead has died.
Jonty Bravery, who is mentally ill, has been jailed for 15 years after throwing a six year old boy from the Tate modern balcony.