LONDON – Competitors at the London Marathon paid tribute to victims of the Boston Marathon attack by observing a 30-second silence before the elite men's race and mass start at 10am.
Organisers at the race, the first event of its type to take place since the bombings in America that killed three people and wounded more than 180, handed out black ribbons to runners, enabling them to display a visible mark of their solidarity.
Geoff Wightman, the event commentator, announced over loudspeakers before the half-minute silence:
"Marathon-running is a global sport. It unites runners and supporters on every continent in pursuit of a common challenge and in the spirit of friendship and fellowship.
"This week the world marathon family was shocked and saddened by the events at the Boston Marathon. In a few moments a whistle will sound and we will join together in silence to remember our friends and colleagues for whom a day of joy turned into a day of sadness.
"Let us now show our respect and support for the victims of the tragedy in Boston."
With 35,000 people estimated to complete the race it is likely that £70,000 – over $100,000 – will be raised.
Race director Hugh Brasher said:
"Everyone connected with the London Marathon was shocked by the terrible events in Boston, and we are keen to show our support to the victims' families and our friends in the running community there.
"As soon as we heard about The One Fund Boston we decided to make a donation. Our pledge to give £2 for every finisher at the 2013 Virgin London Marathon seemed an appropriate and fitting way to make our contribution."
A number of athletes dedicated their races to those affected by the Boston attack. American wheelchair racer Tatyana McFadden was in her hotel room after winning the women's race when the two bombs went off on the finish line.
"I'll be carrying them in my heart as I am running through the course in London," she said. "It's important as an elite runner with a disability to be a role model for those who are newly injured and it's important for me to be an advocate for those. I've lived with many challenges in my life, every single day and so I know something of what it's like."
Another competitor was former England cricket captain Andrew Strauss, who said he wanted to represent the people of Boston and prove that "terrorism doesn't work". He told the BBC:
"It's a horrendous tragedy and I think this is an opportunity for all of us that are involved in the London Marathon to come out and do our bit and show a bit of solidarity and also show that we're not going to cower with fear."
Katherine Jenkins, the Welsh singer, said she was running in memory of her father and to show solidarity to people affected by the bombings in the US.
"Like everyone else, it was just so devastating to see that on the news," she said. "But I think we all feel more than ever that we want to do this and show our support for Boston."
Runners were encouraged to cross the finish line with their hands on their hearts in memory of those killed and injured in Tuesday's attacks. Running organisation Spat, or Social Purpose And Time, which uses running to try and help young homeless people, started a Twitter campaign using the hashtag #handsoverhearts.
Security for the London event was tightened, with 2000 police officers on duty, up 40% on the previous year. Particular attention was placed on the bags of the runners, with 34 lorries taking the rucksacks of the thousands of runners from the start in Blackheath to the finish on the Mall near Buckingham Palace.
The bombs which went off in Boston are believed to have been placed in rucksacks placed on the route.
Chief Superintendent Julia Pendry, who is in charge of London Marathon security, said more search dogs would be deployed and urged marathon spectators to keep their belongings with them to avoid sparking security alerts.
But she added: "There is no link between the Boston Marathon and the London Marathon and there is no change to the threat level at this time to London."
Tributes to the Boston victims had begun several days before the race itself. In the immediate aftermath of the attacks, a wall of encouragement was set up at the accreditation centre for the London Marathon in east London, onto which runners wrote messages of solidarity.