On Monday, for almost the whole daytime, east US metropolis Boston has experienced tight security measures, with the aim to make the 2014 Boston Marathon race, starting at 6 a.m. and finishing at 5 p.m., as one of the biggest and safest in its 118-year old history.

Under protection of more than 10,000 police, army forces, and security company staff as well as close watch by a dozen of helicopters over the sky and hundreds of monitor cameras along race route, the 36,000 runners completed their race safe and sound.

The capacity runners, over 9,000 more than last year, included thousands who were forced to stop last year after the explosions. Last Tuesday, the federal government of the United States hosted a ceremony to mark the first anniversary of the disaster and thousands of people gathered at Boylston Street to pay tribute for victims in the incident.

"I came again and nothing can stop me running here," said New York-based Louis Tekaysa before the finish line on Boylston Street, where two bombs exploded on April 15, 2013 during the 117th race, killing three people and injuring 260 others.

Like Tekaysa, those turned up in this year's race to show their solidarity in sport and love for peace, gained more hails and applause from more than one million spectators, twice the usual crowd, who gathered along the 42km course through eight towns of Boston.

Welson Paul, a local runner, said that this year's registration for the race is not as convenient as before. "But I understand that this is for the sake of safety. The most important for me is to complete the race."

The security implementations that ensured safety of today's race include plainclothes officers, private security contractors, numerous security checkpoints with metal detectors, bomb-sniffing dogs and hundreds of surveillance cameras.

The spectators and Boston residents followed the suggestions to carry their belongings in clear plastic bags to speed up security screening and not to carry backpacks or coolers, wear vests with pockets, or bring baby strollers.

Kerry Perez, a sophomore from Boston University, said that the day is as joyful and peaceful as a usual holiday. "The strict security measures can help people feel safe and help the city to avoid attack by any possible disasters."

Despite the intense security upgrades, authorities and organizers exerted full effort to make the city and the race not appear to be a police state, with the theme to retain the festive and traditional character of the event, the oldest continuously run marathon in the world.

"We are confident that the overall experience of runners and spectators will not be impacted and all will enjoy a fun, festive and family-oriented day," said Kurt Schwartz, director of the Massachusetts Emergency Management Agency.

The marathon is held on Patriots' Day, which falls on the third Monday in April and commemorates the Battles of Lexington and Concord in 1775. It is celebrated in only a few states; in Massachusetts, it is a school holiday, which makes the marathon all the more festive.