Boston - Next year's Boston Marathon will include an additional 9 000 runners, amid a groundswell of support and interest in the wake of the bombing attack this year which killed three people and cut the event short, the marathon's organisers said on Thursday.
Boosting the field size to 36 000 runners at the 21 April 2014 race would make for the second-largest turnout in its history, since 38 708 runners toed the starting line in Hopkinton, Massachusetts at the race's 100th anniversary in 1996.
"We understand many marathoners and qualifiers want to run Boston in 2014, and we appreciate the support and patience that the running community has demonstrated because of the bombings that occurred this past spring," said Tom Grilk, executive director of the Boston Athletic Association, which organises the race.
The increase, a one-time break from the race's normal cap of 27 000 runners, will help to accommodate the 5 624 athletes who were still on the course this year, when a pair of homemade pressure-cooker bombs exploded amid thousands of spectators, volunteers and athletes at the finish line and brought the race to a halt.
The attacks prompted an intense investigation, with law enforcement officials combing both the scene and thousands of still and video images received of Boston's best-attended sporting event.
Three days after the 15 April attack, FBI officials released photos of two men they believed were responsible for the bombing in a plea for the public's help in identifying the suspected bombers.
The pair, later identified as brothers Tamerlan and Dzhokhar Tsarnaev, tried to flee Boston that night, first killing a university police officer in a failed attempt to steal his gun and later engaging in a firefight with police in Watertown, Massachusetts that ended with older brother Tamerlan, 26, dead and younger brother Dzhokhar fleeing the scene.
Most of the Boston area was locked down for the following day while police searched for Dzhokhar, who was found hiding in a boat in a suburban back yard.
Now 20 years old, the surviving brother is awaiting trial on charges, including the murder of four people and using a weapon of mass destruction.
Tsarnaev, a naturalised US citizen, has pleaded not guilty to all charges and may face execution if convicted.
Entry into the Boston Marathon is a prized goal for many US runners, who must meet strict age-graded qualifying times in other marathons to earn a spot at the starting line.
To accommodate an expected surge of interest, race organisers are introducing a staggered registration system, in which runners who have posted times at least 20 minutes faster than the normal qualifying time for their age group will be able to register on 9 September.
Those who have beaten their minimum qualifying time by 10 minutes will enter on 11 September, and those who have run marathons 5 minutes faster than their qualifying time can register on 13 September.
After that, if spots remain, runners who have met their normal qualifying times will have an opportunity to register.
The stricter times could make for a faster-than-usual average field in the 2014 edition of one of America's most elite marathon events.