Updated

The U.S. Secret Service will turn large swaths of downtown Philadelphia into vehicle-free security zones with fenced inside areas during Pope Francis' visit next month.

Mayor Michael Nutter says Thursday some closures will go into effect more than a day before Pope Francis' Sept. 26-27 visit.

Security perimeters are being established around the Benjamin Franklin Parkway and Independence Mall, where Francis is expected to address large crowds,

An inner perimeter will include fencing with portals where people will be required to go through metal detectors. Vehicle-free zones will extend several blocks beyond that.

The security zone for the Benjamin Franklin Parkway will go in effect at 10 p.m. Thursday, Sept. 24. The smaller security zone for Independence Mall will go into effect at 10 p.m., Friday, Sept. 25.