London Marathon pays tribute to Boston victims
21 April 2013 Last updated at 19:46 BST
The start of the London Marathon has been marked by 30 seconds of silence in honour of the Boston bombings' victims.
Thousands lined the streets to see the athletes set off from Blackheath, many wearing black ribbons on their vests.
Three people were killed and more than 170 others injured by Monday's twin blasts, close to the finish line of the Boston Marathon in the US.
David Bond reports.