“My message to Londoners and visitors to our great city is to be calm and vigilant today," Mr Khan said. "You will see an increased police presence today, including armed officers and uniformed officers. "There is no reason to be alarmed by this. We are the safest global city in the world. You saw last night as a consequence of our planning, our preparation, the rehearsals that take place, the swift response from the emergency services tackling the terrorists and also helping the injured.”
22 march: Westminster Bridge,  5 killed, 40 injured by terrorist 
3 June: London Bridge, 7 killed, 48 injured by terrorists

I might not be as "intelligent" as you are but the Mayor's statement is full of ambiguity.  
"We are the safest global city in the world."...
 Just stay away from the bridges. LOL