Harry Potter stars Emma Watson and Daniel Radcliffe are among celebs to have recorded video messages to be played at venues during the London 2012 Olympics

A video featuring stars including actors Daniel Radcliffe and Emma Watson, musician Gary Barlow, boxing star Amir Khan and comedian and actor Simon Pegg will be played at the end of Olympic events.

The five-minute video will be played on screens at a number of venues as spectators leave.

The stars, who are joined by Olympians including Daley Thompson and London 2012 chief Seb Coe, plus a host of other stars including Helen Mirren and Geena Davis, say goodbye and offer advice.

Pegg, who starred in films including Run, Fatboy, Run, ends his message by saying: “Please remember to mind the gap, it’s very important.”

Boxer Khan says: “To all the kids, stay out of trouble.”

Watson, who played Hermione in the Harry Potter films, says: “I hope you had an awesome time, keep loving London.”