06/13/2011 01:45 pm ET Updated Aug 13, 2011

Zombie March Takes Over the Loop With Undead Mob (PHOTOS)

A "flash mob" of a different sort than the ones recent headlines have trumpeted took over the Loop Saturday as Chicago's Zombie March turned out some 500 undead participants, much to the delight and fright of those who reveled in the bloodbath.

The march reportedly kicked off at Millennium Park before heading north along Michigan Avenue toward the Tribune Tower, near which the mob "attacked" a double-decker tour bus. Next, the ruthless gang headed back south toward the WLS's State Street studio, where participants made their plea for brains to the local television audience.

Photographer Ryan Lee Williams survived the event and passed along some shots to Huff Post Chicago. While the participant count was down somewhat from its 2008 count of 1,500 zombies, which reportedly set a world record at the time, this year's edition was undeniably frightening from the looks of it. Check them out below: