Mayor Nutter on Wednesday said spectators will not be permitted to bring bags, or backpacks into the Navy Yard for Sunday's 10-mile Broad Street Run following the deadly bombings at the Boston Marathon.
Nutter also discouraged fans from carrying bags elsewhere along the course, although they are not banned from doing so. Organizers will provide transparent plastic bags to people who need to carry their belongings.
There is no specific threat to Philadelphia, Nutter said, but the city will be on "heightened alert" nonetheless.
In the event of an emergency, Nutter said there will be three evacuation shelters" along Broad Street: Ben Franklin High School, at Spring Garden Street; the School for Creative and Performing Arts, at Christian Street; and South Philadelphia High School, at Snyder Street.
Runners can register to receive emergency-alert text messages at readynotifypa.org.
Philly will be honoring the victims of the Boston bombing. Runners will get "From Philly to Boston with Love" stickers, and participants and fans will be encouraged to donate to One Fund Boston, at onefundboston.org.