The number of police officers patrolling the Boston Marathon this year, will be doubled to numbers over 3,500.
One year after two bombs exploded near the finish line.
The enhanced police presence is part of a new security plan.
Police are looking to spectators to be especially vigilant and report any suspicious items or activity.
Spectators who attend the marathon are being discouraged from bringing backpacks, bags, coolers and other large items.
They are being asked to carry personal items in clear plastic bags.
Anyone who does bring a bulky bag will be subject to search.
Authorities said they want to balance keeping the traditional feel and character of the marathon and tightening security.
”We are confident that the overall experience of runners and spectators will not be impacted, and that all will enjoy a fun, festive and family oriented day,” said Kurt Schwartz, director of the Massachusetts Emergency Management Agency.
Runners and spectators are being told they can’t bring containers with more than 1 liter of liquid and also can’t wear bulky costumes or anything that covers their faces.
Police and public safety officials from cities and towns along the marathon course have been meeting for to come up with a plan to beef up security.
Dzhokhar Tsarnaev the alleged bomber pleaded not guilty to 30 federal charges and faces the possibility of the death penalty. His brother, Tamerlan Tsarnaev, died following a shootout with police several days after the bombing.
FBI and its law enforcement partners have met with officials in other cities that host large-scale public events, including London and New York City.
Police will have more than 100 additional security cameras along the route and have also met with business owners to coordinate use of their surveillance cameras.
Spectators are urged to report anything at all suspicious to police.