A flashmob of nearly 1,000 people gathered in London's Trafalgar Square on Saturday and froze for five minutes, causing confusion among tourists and passers-by.

The meeting was arranged on Facebook in response to a similar stunt in New York's Grand Central Station earlier this year.

Participants gathered in Trafalgar Square and froze in their positions while organisers circled with video cameras recording reactions.

"It was a fun way to spend a few minutes," said one of the participants. "I was a little shocked about how many people took part but hey, that's viral ideas for you. You never know how big they're going to get."

Participants froze in mid-kiss, while drinking from bottles or on the ground after mock bicycle collisions at 3.30pm on the dot and then carried on their business at 3.35pm after giving themselves a short round of applause.