Dramatic footage captures Boxing Day shoppers sprint in fear from a packed shopping centre today.
A man wielded a knife at Stratford Westfield in east London.
Dozens of Metropolitan Police can be seen descending on the popular shopping centre in other pictures and video.
But it has emerged these shoppers had become startled after hearing a countertop smash in the food court in an unrelated incident.
Alicia Porter, who witnessed the drama unfold, said on Twitter: "There were was a very loud noise, lots of screaming and a crowd of people running a sprinting for exits".
Another witness said: "Apparently some people broke a glass window in the food court."