Thousands of marathoners took to the streets of Boston on Tuesday, as the city honoured three killed and more than 260 injured in a bomb attack last year. Dignitaries, spectators and more than 36,000 runners observed a moment of silence before the race began. The heavy security operation included a ban on rucksacks and screening at checkpoints.
US runner Meb Keflezighi and Rita Jeptoo from Kenya won the men's and women's races.
Athletes with disabilities were the first competitors to set off, at 08:50 local time. The elite women's race started at 09:32, with the elite men setting off half an hour later, followed by thousands of other runners.
Keflezighi is the first US runner to take the title since 1985. He clocked in at 2 hours, 8 minutes and 37 seconds.