LONDON — As police in Massachusetts hunted down and traded fire with the men suspected in the marathon bombings in Boston, Scotland Yard said Friday that it had increased the number of officers assigned to guard the London Marathon by several hundred to reassure runners and spectators of their safety on Sunday.
The London event, one of the world’s biggest with tens of thousands of competitors and many more onlookers, is the first major international race of its kind since Monday’s bombings in Boston killed three people and wounded more than 170. The 37,000 runners include many stars, like the British Olympic gold medalist Mo Farah, who is running only the first half of the race.
The finish line of the event lies within sight of Buckingham Palace on the broad avenue called the Mall. At the starting line, runners are to pause for a 30-second silent commemoration of the dead in Boston, and the organizers say they will hand out black armbands for contestants.
Chief Superintendent Julia Pendry, who is in charge of the policing of the London Marathon, said additional deployment would increase the number of officers by 40 percent compared with last year.
She did not give a precise figure for the number of officers to be deployed. The number of spectators at the event runs into hundreds of thousands.
The British police say they are in close touch with their counterparts in Boston and have received no indication that the attack in the United States is part of a broader conspiracy involving London.
‘‘The message I’d like to give to everybody coming is that we want you to come on Sunday, enjoy coming to watch your family and friends race, but please look after your own belongings because unattended packages will cause us to have more work to do,’’ Pendry said.