n the spring sunshine they gathered in their thousands, black ribbons pinned to their running vests. And before they took their first step, they stood in silence with their heads bowed in honour of those killed and injured in the Boston marathon bombings last week. This was the moving scene at the start of the London marathon yesterday as Prince Harry praised the defiant British spirit that saw 37,000 runners take part in the race amid heightened security. Scroll down for video Capital weather: Spectators enjoy the sunshine and watch as runners cross Tower Bridge in the 33rd London Marathon And they're off: The 36,000 runners get underway this morning. The Metropolitan Police drafted in extra officers after the Boston attacks Carnival atmosphere: Crowds turned out in their thousands to support the runners Paying tribute to the victims of the Boston bombings, Harry applauded the way everyone had come together to run and raise money for good causes. ‘It’s fantastic, it’s