Unveiling a portrait of Dr Chad Varah, the charity's founder, the Prince of Wales said: "I am deeply appreciative and full of admiration of everything these remarkable volunteers do; that you give up so much of your time and provide your love and compassion in this way."
More top news
Dozens of plots have been thwarted since July 7, 2005, but are we any less vulnerable to terror attacks?
While #SevenSeven has been trending for much of the day, so too has the #WalkTogether campaign.
Police want to find four boys seen on CCTV around the time of the attack.